Inside-Out Neapolitan Layer Cake

Inside-Out Neapolitan Cake via Sweetapolita

I have great news! My temporary cake-diet, you know, the one during which I stopped eating cake, is over, and I’ve resumed my more permanent cake-diet, the one where all I think about and often indulge in cake. And, let me say, I ended it and restored order just in time: 3 layers of rich Southern Devil’s Food Cake stacked between fluffy Neapolitan flavoured Swiss Meringue Buttercreams: Belgian Chocolate, Vanilla, and Strawberry, and topped with pure dark chocolate sprinkles from Holland. If you read the past post of mine, Neapolitan 5-Layer Birthday Cake with Strawberry Frosting, you’ll recall that I adore Neapolitan. In that case, the cake itself was Neapolitan. The flavours really bring me back to my childhood, and I was so happy to see that so many of you felt the same way after reading that post. Lately, I’ve been thinking more and more about Neapolitan and how I think there may be a serious shortage of it in my day-to-day life, so I’ve been dreaming up new ways to incorporate it into my world. This was a really fun start to that mission!  

Inside-Out Neapolitan Cake via Sweetapolita

If someone was ever cruel enough to force you to choose, would you say that you’re a cake person, or a frosting person? I find the older I get, the more I appreciate the cake itself. I would say that most times I would be perfectly content with a fresh piece of cake icing free, but wow, Swiss Meringue Buttercream makes me so very happy, and I’m pretty sure, with some focus, I could sit down and eat an entire bowl of it. Of course, its rich-but-light texture that’s not too sweet but just sweet enough is a dream in itself, but working with it, well, there’s just nothing better. It’s so satiny and holds up so well under fondant, on its own, in ruffles, smooth & perfect, or just about any way at all. You can flavour it with just about anything, and it can be frozen, then thawed, refrigerated, then room temperature–it will take just about anything! It may seem intimidating to make at first, but it’s really quick once you get the hang of it, and you will never look back. It’s also a really great way to take a simple layer cake and make it a bit more special and luxe.

Inside-Out Neapolitan Cake via Sweetapolita

As for the cake itself, I decided to take a break from my favourite Dark Chocolate Cake and go for a really rich and decadent Southern Devil’s Food Cake recipe I found, from Fine Cooking, that’s made with a few different ingredients than my usual recipe, such as mayonnaise, butter, and dark brown sugar. I did, though, make sure to include my must-have cocoa powder, Cacao Barry Extra Brute, for that really dark and rich taste. Divine. I really can say that I notice that extra richness that the butter and mayonnaise add–incredible!

Inside-Out Neapolitan Cake via Sweetapolita

What better way to show off all of these buttercream flavours, than to just tie it into the design of the cake, and leave the frosting off of the outside? I personally love cakes that are left open like this, and I think it’s a really refreshing change once in awhile, particularly when you play with interesting filling flavours, textures, and colours. Now, I did go quite generous with this filling because of the gorgeous, not-so-sweet Swiss Meringue Buttercream, but I wouldn’t recommend this with sugary frosting. As a “rule,” not that I’m big on those, you would aim for your layer-cake filling to be about 1/2 of the thickness of your cake layers.

Inside-Out Neapolitan Cake via Sweetapolita

I sliced this piece for the photo, and then covered it with wrap once I was done with the photographs. I wasn’t going to eat it (I promise), but then as the girls were walking to the bathroom for bath-time, they discovered it, and well, there we sat in the upstairs hallway sharing this with 3 forks and a lot of “mmmm”s. Nothing could have prepared me for the extreme cute that is watching a 4-year-old and a 19-month-old eat cake and sprinkles while sporting bare bums.

Sprinkles via Sweetapolita

Speaking of sprinkles, I have to tell you about this incredible range of imported sprinkles I found at the cutest little bakery and European grocer located in a wee little town near me, Orono, where I buy most of my antiques. I was there this past weekend, and I discovered an entire shelf of these gourmet sprinkles from the Netherlands. Aside from the fact that they offer pure dark chocolate, milk chocolate, anise, and many more sprinkle variations, they won me over at first glance–can you guess why? Yes! They have smothered these sprinkles all over toast, and this is, what I since discovered something the Dutch love to do! I can’t say it ever crossed my mind to do that, but I think I need to give that a try–immediately. Besides, any country that swears by mayonnaise and french fries is clearly on the brink of culinary genius (did I mention that the little grocer also sells large squeeze bottles of the french-fry-designated mayo?), and I trust them completely. I sprinkled a handful of the dark chocolate variety as the finishing touch to this cake. Love them! You can learn more about these De Ruijter sprinkles here or buy them here.

I hope you enjoy this cake as much as my bare-bummed little cakelets and I did.

Inside-Out Neapolitan Layer Cake

Yield: One 3-layer, 8-inch round cake


    For the Cake:
  • 3/4 cup (170 g) unsalted butter, softened
  • 2 cups (460 g) packed dark brown sugar
  • 2 teaspoons (10 ml) pure vanilla extract
  • 3 eggs, at room temperature
  • 1-3/4 cups (220 g) all-purpose flour
  • 3/4 cup (90 g) unsweetened Dutch-processed cocoa powder
  • 1-1/4 teaspoon (7 g) baking soda
  • 1 teaspoon (5 g) baking powder
  • 1 teaspoon (10 g) kosher salt
  • 1-1/2 cup (360 ml) buttermilk, at room temperature
  • 1/4 cup (59 ml) mayonnaise
  • For the Buttercream:
  • 5 large fresh egg whites (150 g)
  • 1-1/4 cup (250 g) superfine granulated sugar
  • 1-1/2 cups (340 g) (3 sticks) unsalted butter, softened, cut into cubes
  • 2 teaspoons (10 ml) pure vanilla extract
  • pinch of salt
  • 5 oz (150 g) quality bittersweet chocolate
  • Few drops Strawberry Flavor Oil, or 2 tablespoons (30 ml) strawberry puree
  • Few drops pink gel colour


    For the Cake:
  1. Preheat oven to 350° F. Butter three 8-inch round cake pans, line with parchment rounds, and dust with flour, tapping out the excess.
  2. In a stand mixer fitted with the paddle attachment, beat the butter, brown sugar and vanilla on medium-high speed until lighter in color and slightly increased in volume, about 5 minutes. Lower the speed to medium and add the eggs, one at a time, mixing until each is fully incorporated before adding the next.
  3. Sift the flour, cocoa powder, baking soda and baking powder into a medium bowl. Add the salt to the dry ingredients after sifting, and whisk dry ingredients.
  4. Alternate dry ingredients and buttermilk into creamed mixture, beginning and ending with dry ingredients. Mix until just incorporated, or finish by hand gently. Fold mayonnaise into batter with a whisk, until just blended.
  5. Divide the batter evenly between the prepared pans. If possible, weigh the batter in each cake pan for 454 g each (excluding the pans--you will want to tare the scale each time.) This ensures even layers. Smooth with small offset palette knife, and bake for about 30 minutes, rotating once after 20 minutes. Cake is done when toothpick or skewer comes barely clean. Try not to over-bake. I tend to under-bake a few moments, so the skewer is a little bit gummy. This works well for a moist chocolate cake (not vanilla).
  6. Let pans cool on wire rack for 20 minutes, then invert cakes onto racks, gently, peeling away parchment rounds. Let cool completely.
  7. For the Buttercream:
  8. Wipe the bowl of an electric mixer with paper towel and lemon juice, to remove any trace of grease. Add egg whites and sugar, and simmer over a pot of water (not boiling), whisking constantly but gently, until temperature reaches 160°F, or if you don't have a candy thermometer, until the sugar has completely dissolved and the egg whites are hot.
  9. Place bowl back on mixer and fit with whisk attachment. Whip until the meringue is thick, glossy, and the bottom of the bowl feels neutral to the touch (this can take up to 10 minutes, or longer). Switch over to paddle attachment and, with mixer on low speed, add softened butter in chunks until incorporated, and mix until it has reached a silky smooth texture (if curdles, keep mixing and it will come back to smooth).
  10. Add vanilla and salt, continuing to beat on low speed until well combined.
  11. Assembly of the Inside-Out Neapolitan Layer Cake
  12. Divide buttercream into 3, and flavour 1/3 chocolate and another 1/3 strawberry. Leave remaining buttercream vanilla. For chocolate, add melted and cooled bittersweet chocolate and blend until combined. For strawberry, add a few drops of Strawberry Flavor Oil (minimal) or 1-2 tablespoons of strawberry puree. Add a few drops of pink gel food colouring to strawberry buttercream
  13. Trim any doming on your cake layers with a very sharp, serrated bread knife. Wrap layers in plastic wrap and chill for 15 minutes in freezer.
  14. Spread a 1" circle of icing onto an 8" round thin cake board using an offset palette knife and place the first cake layer on top, face-up.
  15. Using a small offset palette knife, spread 1 cup of chocolate buttercream on top, leaving about a 1" gap from edges. Place second cake layer on top, face up, and repeat, using Vanilla Buttercream.
  16. Place final layer on top, face-down and repeat using Strawberry Buttercream.
  17. Fill 3 piping bags with remaining buttercreams fitted with Wilton 8B decorative tip, or the tip of your choice, decorate edges, filling in gaps. Top with dark chocolate sprinkles.


*Keep buttercream in airtight container in refrigerator for up to one week, leaving out at room temperature when needed, rewhipping in mixer for 5 minutes.

**Can freeze buttercream for up to 6-8 weeks. To thaw, place on counter overnight, and rewhip for 5 minutes with paddle attachment in an electric mixer.

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[Southern Devil's Cake Recipe adapted from Fine Cooking, by David Guas]

Good luck & enjoy!



PS. I love receiving your baking questions, and I find it works really well if you ask them in the comments section, so that when I reply to post-related questions in the comment section as opposed to via email, other readers with the same questions can read the information as well. Thanks so much!

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