This apple spice cake is, no lie, the best cake I’ve ever made. And I’m not just saying that because I developed the recipe for my wedding cake – I’ve made it this week for the blog (and for Jackson to share with his co-workers), and I’m making it again next week for Thanksgiving dessert.
It’s the most perfect fall dessert I can imagine – moist but not dense cake that has a pronounced, but not cloying, spice presence, punched up with cinnamon and apple scented caramel, sauteed apples, and a brown butter bourbon buttercream that I would eat straight off a spoon.
Of course, eating it was the easy part. Figuring out how to make it was a little harder.
Hang onto your butts. It’s going to be a long one.
The apple spice cake
I’m not going to spend a great deal of time here explaining how I figured out the apple spice cake recipe – I have a whole video of me vlogging the process elsewhere on this site if you want to check it out. The short version is that I found two recipes, decided which I liked more, and then continued to mess with it until I had something that I felt was perfect.
The caramel
I had grand plans to develop my own caramel sauce recipe in the same way I developed the cake – but the problem was that I already knew what I wanted. I went through the motions of trying two different recipes (both of which failed, by the way. And let me tell you how unpleasant it is to scrape separated, greasy, hardened caramel out of your bowls), and then did what I should have done all along, which was to modify Smitten Kitchen’s apple cider caramels into the sauce of my dreams.
Although I suppose “sauce” here might be misleading.
I wanted a soft, pourable caramel that would hold its shape at room temperature without ripping anyone’s fillings out – in short, I wanted something that sits right in between sauce and candy. This took me a while to figure out (and even now I’m not sure I’ve nailed it) because caramel and sugarwork in general is a dark magic that I don’t fully understand.
What I did know, though, is that I had basically two routes to thin down the caramel. I could add more fat/liquid, which would thin the sauce by basically overwhelming the thickening power of the cooked sugar, or I could cook the sugar to a much lower temperature.
I was hesitant to go with the first option – the apple cider kick in the caramel was important to me, and I was afraid that if I added more cream or butter that it would mute that flavor.
So I started to experiment with temperature.
The original recipe called for cooking the caramel mixture to 252°F, or the early end of hard ball – which makes perfect sense for a candy, but won’t work for what I’m looking for. I figured I should aim for something more along the lines of late thread or early soft ball – around 235°F. This did result in a thinner, more sauce-like caramel, but I found that it was still a bit difficult to spread (and by “a bit difficult” I mean that if the sauce cooled at all while I was working with it, it had a tendency to rip chunks out of my cake).
I didn’t want to mess with the temperature any more, since I was afraid cooking it any less would result in both a less caramel-y caramel and a sauce that was just way way too thin. So I added about 10 percent more heavy cream, figuring that it was better to start slow and adjust by adding more cream at the end, rather than way overcorrecting and ending up with something that was way too thin to be usable.
Friends, it worked. That tiny bit of extra cream pushed the sauce from slightly too thick to absolutely perfect – although neither Jackson nor I had any complaints about eating either version over ice cream or leftover apple spice cake test cupcakes for the rest of the week.
The buttercream
Some backstory – I made this brown butter bourbon frosting for the first time for a friend’s wedding. It was absolutely delicious, but working with it almost made me lose my religion. It was so incredibly soft and slippery – even inside a climate-controlled building in late December, I spent the whole evening worried that the frosting was going to soften so much that the cake would collapse. Fortunately for everyone involved it didn’t – but it did leave me with a strong desire to fix the frosting.
The concept was so good! I just needed to figure out how to make it stable – especially since I didn’t want to spend a chunk of my own wedding worrying that the cake was going to collapse.
And the frustrating thing was, research didn’t help me much. Googling “brown butter Italian meringue buttercream” got me lots of results from people who claim to have gotten perfect results from a one-to-one swap of browned butter for whole, but my lived experience didn’t bear that out.
So I started looking into the chemistry of butter, doing research on fat crystal structures before and after melting, and looking to see if Italian meringue buttercream needed a certain percentage of water to stay stable.
And again, I got almost nothing usable.
So I decided to go for it and just experiment wildly.
I had two working theories for why the frosting wasn’t behaving. First, the frosting needed the water in the whole butter to hold the emulsion properly – so I decided to try adding back the water that got evaporated off during the browning process. Second, that the structure of the fat crystals changed dramatically during browning and as a result wouldn’t hold as well in the frosting – so I decided to go half and half on the brown butter and whole butter to see if the structure of the whole butter could make up for the lack.
And then for kicks and giggles I tried Swiss meringue buttercream with all brown butter under the logic that my one disastrous attempt at dairy-free Italian meringue buttercream had failed miserably – but swiss meringue buttercream worked well. Maybe what works with fake butter would work with browned butter?
Turns out that was a false equivalency – the Swiss meringue buttercream was the worst of the lot. It was a soupy mess that wouldn’t come together in spite of almost 30 minutes of beating both before and after refrigeration. And, to top off the unpleasantness, developed a weird surface crust while I was working on other frosting tests.
Needless to say, that one was not a keeper.
The water-added brown butter Italian meringue buttercream went significantly better. It was thicker than the all brown butter frosting, but it was still so soft that it wouldn’t hold to a spatula and had an unpleasantly chunky texture.
Fortunately for both me and my sanity, the half-and-half test worked perfectly. It had the incredibly fluffy, silky texture that Italian meringue buttercream is known for, held onto a spatula even when I turned it upside down, and, best of all, had an intense brown-butter flavor that wasn’t muted at all by the whole butter.
Do I know why this works? No. Does this frustrate me? Yes, absolutely. I want to do more research, but I think it will involve reading some incredibly dense food science papers and I’m not sufficiently recovered from wedding planning to deal with that yet.
Apple spice cake: the final form
Once I got the frosting figured out, putting everything together was easy.
I have to admit I was a bit nervous about debuting this recipe at my own wedding. The apple spice cake bakes up extraordinarily flat and level, so I couldn’t do my usual final flavors quality control check with the scraps. I loved all the parts and pieces individually, but there was this lingering concern that they wouldn’t come together the way I had planned.
I shouldn’t have worried.
This is unquestionably the best cake I’ve ever made – I think you can see it in my face.
I can’t wait for you to try this – it’s a bit of work, but worth every step of the process. I can’t think of a better thing to take to a Thanksgiving gathering next week.
Apple spice cake
Yield: 2 8-inch cakes Time: approximately 1 hour Source: Inspired by Sally’s Baking Addiction
- 268 grams (1 ¾ cups) all-purpose flour
- 7 grams (1 ½ teaspoons) baking powder
- 5 grams (¾ teaspoon) baking soda
- 3 grams (¾ teaspoon) salt
- 228 grams (2 sticks) unsalted butter
- 5 grams (2 teaspoons) cinnamon
- 2 grams (1 teaspoon) ginger
- 3 grams (1 ¾ teaspoon) cardamom
- 1.5 grams (1.5 teaspoons) nutmeg
- 302 grams (1.5 packed cups) dark brown sugar
- 154 grams (heaped ½ cup) unsweetened applesauce
- 4 whole eggs
- 7 grams (2 teaspoons) vanilla
- 154 grams (about one large) granny smith or other tart baking apple, peeled and grated
Preheat your oven to 350°F. Grease two 8-inch round cake pans and line the bottoms with rounds of parchment paper
In a small bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside for now.
In a small saucepan over medium-low heat, melt the butter, then keep cooking, swirling or stirring the liquid constantly, until it is an amber-red-brown and nutty smelling. You want it deep brown, but not burnt. Once it reaches this stage, remove it from the heat and quickly pour it off into a small heatproof bowl, making sure you scrape every last brown bit you can from the bottom of the pan. Stir your spices into the hot butter – it’ll foam up a bit, but keep stirring until it settles down. Set this aside for now.
In a medium bowl, whisk together the sugar, applesauce, eggs, and vanilla. Whisk in the butter and spice mixture, then add the flour. Gently fold with the whisk until almost all the flour is gone, then add the shredded apple. Fold until the apples are evenly distributed and no dry flour remains.
Divide the batter between the two prepared pans and bake until the cake springs back when pressed and is beginning to shrink away from the sides of the pan, 25-30 minutes.
Allow to cool completely before filling and frosting.
As long as they’re wrapped tightly, the baked cakes will keep beautifully in the freezer for up to 6 months.
Apple cider caramel sauce
Yield: 1 pt Time: 45-60 minutes Source: Adapted from Smitten Kitchen
- 473 grams (1 pint) unfiltered apple cider
- 0.5 grams (¼ teaspoon) ground cinnamon
- 2 grams (1/2 teaspoon) Maldon or other flakey salt
- 56 grams (½ stick) unsalted butter
- 100 grams (½ cup) granulated sugar
- 55 grams (¼ cup packed) dark brown sugar
- 55 grams (¼ cup) heavy cream
In a medium saucepan, boil the apple cider over medium high heat until it has been reduced to between 3 tablespoons and a quarter cup of liquid. It should be quite dark and syrup-y – the bubbles should start stacking like they would if you were boiling sugar for candy. On my stove, this takes about 30 minutes, but I would watch closely since stoves vary so widely.
While that’s happening, stir together the salt and cinnamon in a small bowl and set them aside. This feels unnecessary, I know, but blending the cinnamon into the salt means it won’t clump together into an impossible-to-break-up cinnamon ball when you add it into the caramel (please don’t ask me how I figured this out…).
When the cider has reduced, take it off the heat and add in the butter, both sugars, and the heavy cream. Return to the heat, and allow it to boil until the syrup reaches 230-235°F. If it goes hotter than this, it’s not the end of the world – your caramel will just be more taffy or candy-like when it cools and you’ll have to heat it to make it pourable. Just don’t let it go above 250°F or you’ll have hard candy.
Once it comes up to temperature, remove the sauce from the heat and add the salt/cinnamon mixture and stir it well.
Pour it into a heatproof jar or other container and allow to cool completely before using. The caramel sauce will keep for three weeks in the fridge, or up to three months in the freezer.
Brown butter bourbon Italian meringue buttercream
Yield: About 4 cups Time: 20 minutes Source: The Eighth Street Mess
We’ve made Italian Meringue Buttercream (or IMBC) around here before – if you need another perspective on the recipe, feel free to check out the lemon-blueberry cupcakes!
As written, this will make enough to frost one 8-inch layer cake – but only just. If you’re not confident in your frosting abilities (or just don’t feel like playing icing chicken, or want enough to pipe decorative blobs or swags) I would recommend doubling the recipe.
- 226 grams (1 cup) granulated sugar, divided
- 128 grams (4 ea) egg whites
- 170 grams (1.5 sticks) unsalted butter, browned and allowed to solidify overnight
- 170 grams (1.5 sticks) unsalted butter, softened
- 9 grams (2 teaspoons) vanilla extract
- 20 grams (5 teaspoons) bourbon
In the bowl of your stand mixer, combine the egg whites and 56 grams (¼ cup) of the sugar.
Mix the remaining 170 grams (¾ cup) sugar with 56 grams (¼ cup) of water in a small pot and bring to a boil over medium-high heat. When the sugar starts to boil, begin whipping the egg whites with the whisk attachment on your stand mixer. If you’re worried about the sugar syrup crystallizing, you can brush down the sides of your pot with a wet pastry brush.
When the sugar hits about 230°F (110°C), increase the mixer speed to maximum – your egg whites should hit stiff peaks about the same time the sugar finishes cooking at 235 – 240°F (113 – 115°C). If it’s a little short, that’s fine – your frosting will still turn out ok. You just don’t want to overwhip your egg whites.
Drop your mixer speed to low, and slowly (and carefully) stream the hot sugar syrup into the space between the bowl and the spinning whisk. Once all the syrup is in, increase the speed to high (between 8 and 10, depending on your machine) and whip until the meringue is glossy and the bowl is cool to the touch. This can take 10 minutes or so, so be patient. If you’re in a rush, you can wrap flexible ice packs (or Ziplocks filled with ice cubes) around the bowl to help things cool down faster.
Once the meringue is cool, begin adding in the butter. It is super important that your butter is at room temperature – you want it soft enough that it’s not going to just bounce around and deflate your meringue. Plus, the closer your butter and meringue are to the same temperature, the more likely it is that your frosting will skip the terrifying soup-to-curdled-goop phase. Add the butter a few pieces at a time, making sure they are fully incorporated before you add the next batch.
Once all the butter is in, keep whipping until the mixture forms a fluffy, spreadable frosting. It may do this right away, or it may start looking soupy or curdled. I find that brown butter goes too soft way more easily than whole butter, so it’s pretty common for this frosting to stay soupy. If it hasn’t smoothed out and gotten fluffy in 10 minutes or so of whipping the hell out of it, pop your bowl of frosting into the refrigerator for half an hour or so, and then try whipping it again.
When your frosting is lovely and smooth and fluffy, beat in the bourbon and vanilla.
Store the frosting in an airtight container in your refrigerator for up to a week, or in your freezer for up to three months. Just make sure you let it come all the way up to room temperature before you try to use it!
Sauteed Apples
Yield: About a pint Time: About 30 minutes Source: The Eighth Street Mess
- 2 tablespoons unsalted butter
- 3 granny smooth or other tart baking apple, peeled and cut into small dice
- ½ teaspoon cinnamon
- ¼ teaspoon ginger
- ⅛ teaspoon nutmeg
Melt the butter in a large saucepan or pot over medium high heat. Once the foaming subsides, add the diced apples and spices, drop the heat to medium, and cook until the apples are slightly translucent, but not yet losing their shape, 5-8 minutes.
Cool completely before using in the cake.
The sauteed apples will keep in the fridge for up to a week.
To assemble the apple spice cake: Using a long, sharp serrated knife, carefully split each cake layer in half horizontally. You should now have four one-inch-thick-ish cake layers from the two two-inch-ish thick cake rounds you started with.
Place a layer of cake onto a plate or board and brush it down with a little bit of apple cider – you want the whole surface moist, but not soggy. Using a piping bag with a large round tip (or a ziplock bag with a ¼-inch-ish hole cut into the corner), pipe a ring of buttercream all the way around the edge of the cake. You’re essentially using the buttercream as a dam to prevent all your gooey caramel and apples from squidging out the side of the cake.
Spread about ⅓ cup of your caramel sauce evenly over the cake inside the ring of frosting, then sprinkle about half a cup of sauteed apples over the caramel. Place the next round of cake on top of the apple/frosting/caramel and repeat until you’ve used all your cake rounds.
Now all that’s left is to frost the cake! I like to do a crumb coat first, especially on this apple spice cake, which sheds crumbs like crazy. Spread the thinnest layer of frosting you possibly can all over the cake – think those semi-naked wedding cakes that have been so popular lately.
If your cake is particularly unstable-feeling or if you’re worried about crumbs continuing to come up, pop your cake in the refrigerator for 15-30 minutes, long enough for the frosting to set hard enough that you can touch it without any coming off on your finger.
Now you can fully frost the cake. I like to start by blobbing a whole bunch of icing on the top, and spreading it to the edges of the cake so the top is smooth and the icing is as thick as I want it. This usually leaves a big ring of excess frosting hanging over the sides – don’t try to take this off! Instead, use your spatula to push it down the sides of the cake, adding more frosting as needed to fully cover.
If you have any caramel left over, it’s lovely to drizzle that over the top of the cake as a final touch.
