What is this sprinkle-crusted cakey-ness? It's a 6-layer moist chocolate cake, filled with vanilla birthday cake whipped cream filling (we'll get to that yumminess), covered in malted Belgian chocolate frosting, then covered with a medley of sprinkles and such. Inspired by one of my favourite cake recipes, the Campfire Delight Cake, I've been thinking a lot about 6-layer chocolate cakes covered in malted Belgian chocolate frosting -- it's just too awesome to not. But with all of that chocolate going on, 5 layers of vanilla birthday cake whipped cream filling push the party in this cake over the edge. So decadent! I absolutely love whipped cream filling. I think it's such a great starting point for a filling, and you can flavour it pretty much any way you like. It's so light and airy, and because it's not sweet or buttery, it's the perfect filling for a rich cake frosted with a rich icing. So I just took that whipped cream filling and turned it into a vanilla birthday cake of sorts! With some white cake batter, pure vanilla and rainbow sprinkles that classic whipped cream filling just had 8 excitable little girls show up to the door with their party hats on. 
I thought it would be fun to make a huge sprinkle medley to decorate this cake, so I just grabbed a big bowl along with a bunch of jars of my favourite sprinkles and sugar pearls, and kept adding and shaking them up until I liked the way it looked. I decided to pipe a fancy border around the top, mostly because I love the consistency of that chocolate frosting, and I knew most of the cake surface would be covered with sprinkles. Crunchy, creamy, cakey, fluffy, chocolaty. The border is created with a 1M star tip, and rather than just piping one "shell" after the other in a straight single line around the top of the cake, I angled the first one toward the centre slightly, and then piped another right beside it, angling it toward the first -- like a heart shape. Once you do this around the whole cake, it takes on a woven look of sorts. Really quite simple, but neat looking! 
And then I started daydreaming frolicking in a huge adult-size play area filled with 5 feet of this sprinkle medley. And then I had cake. And then I did a few jumps for joy! And then I got a cramp. But then I jumped for joy again! I simply cannot wait to share more book details with you all. Stay tuned! In the meantime, please say you'll make this cake to help me celebrate?
6-Layer Chocolate Sprinkle Cake
6 layers of moist, dark chocolate cake filled with birthday cake whipped cream and sprinkles, covered in creamy, rich malted Belgian chocolate frosting and covered in a medley of more sprinkles.
For the Chocolate Layer Cake:
- 2-1/2 cups + 1 tablespoon (330 g all-purpose flour)
- 3 cups 600 g granulated sugar
- 1 cup + 1 tablespoon (135 g Cacao Barry Extra Brute Cocoa Powder (or similar premium brand))
- 1 tablespoon 15 g baking soda
- 1-1/2 teaspoons 7.5 g baking powder
- 1-1/2 teaspoons 12 g salt
- 3 eggs (at room temperature)
- 1-1/2 cups 360 mL buttermilk, room temperature
- 1-1/2 cups 360 mL strong black coffee, hot
- 1/2 cup 120 mL vegetable oil
- 1-1/2 tablespoons 22.5 mL pure vanilla extract
For the Whipped Birthday Cake Filling:
- 3 tablespoons 45 ml cold water
- 1 tablespoons 15 ml unflavoured gelatin (such as Knox brand)
- 2 cups 500 ml whipping cream (35-37% fat), cold, divided
- 1/2 cup 63 g icing sugar
- 1 heaping tablespoon (15 g white cake mix)
- 1 teaspoon 5 ml pure vanilla extract
- Pinch of salt
For the Malted Belgian Chocolate Frosting:
- 1 lb butter (2 cups(454 g), at room temperature)
- 4 cups 500 g icing sugar (confectioners' or powdered), sifted
- 3/4 cup 75 g Ovaltine Classic (brown in colour)
- 1 tablespoon 15 mL pure vanilla extract
- Pinch of salt
- 8 oz 250 g quality Belgian chocolate, chopped, melted and cooled
- 1/2 cup 120 mL whipping (35% fat) cream
You will Also Need:
- Sprinkles! Lots of them (about 2 cups, preferably a mix - see notes for suggestions!)
For the Chocolate Layer Cake:
- Preheat oven to 350° F. Prepare three 8-inch round cake pans (butter, line bottom with parchment paper, butter paper, dust with flour).
- In bowl of electric mixer, sift all dry ingredients, including sugar. Combine eggs, buttermilk, coffee, oil and vanilla in a measuring cup and beat lightly with a fork.
- Add milk mixture to the dry ingredients mix for 2 minutes on medium speed (you may need the plastic splash-guard that comes with mixer). Divide batter evenly among prepared pans. (Batter will be thin.)
- Bake for 20 minutes and rotate pans in oven. Continue to bake until toothpick or skewer comes almost clean (a few crumbs), about 12 more minutes. Cool on wire racks for 20 minutes then gently invert onto racks until completely cool.
For the Whipped Birthday Cake Filling:
- In a small bowl, place the cold water and sprinkle with the gelatin. Let sit for at least 10 minutes. In a small saucepan, bring 1/3 cup of the cream just to a simmer, then stir into the gelatin mixture. Refrigerate, stirring frequently, until cool but not set, about 8 minutes.
- In a small bowl, sift together the icing sugar and cake mix.
- In a chilled stainless steel bowl with a chilled whisk attachment (for stand mixer), beat the remaining whipping cream, icing sugar/cake mix, vanilla and salt until it thickens just slightly and soft peaks begin to form, about 1 minute. Very gradually add the gelatin mixture and continue beating until medium-firm peaks form (should be thick enough to spread). Keep covered and chilled until ready to use.
For the Malted Belgian Chocolate Frosting:
- In a bowl of stand mixer fitted with paddle attachment, combine the icing sugar and butter and beat on low speed for about 1 minute.
- Add malt powder, vanilla and salt, and beat on low until well combined. Add the melted chocolate and beat on medium speed until smooth (about 2 minutes).
- Add whipping cream and beat on med-high speed for another minute.
- Mix and "work in" with rubber spatula right before applying to cake (to rid of air bubbles).
Assembly of the 6-Layer Chocolate Sprinkle Cake:
- In a medium bowl or container, create a mixture of your favourite sprinkles: non-pareils, rainbow jimmies, chocolate sprinkles, pearls, etc. Set aside.
- On an 8-inch round cake board (or cake plate), put a small dollop of frosting. Cut your 3 cake layers each once horizontally with a long, serrated knife, so you have a total of 6 layers.
- Place your first layer face-up on the board (or plate) and cover with 1/5 of the Whipped Birthday Cake leaving about 1/2" around the edge and cover with a thin layer of your favourite sprinkle mix.
- Repeat until you come to your final layer, which you will place face-down. If you find the cake too soft and unstable, put in refrigerator for a few moments to firm it up, then resume.
- Using a turntable, if possible, frost entire outside of cake with a thin layer of Malted Belgian Chocolate Frosting to seal in crumbs. Chill until firm. Repeat with another layer of frosting, this time working to get the frosting as smooth as possible. Place cake on a cookie sheet and carefully press your sprinkle mix onto sides, letting the excess fall down onto the cookie sheet. You can cover sides completely or leave 1/3 exposed (as in photo). Once you are pleased with your sprinkled sides, fill a medium or large pastry bag fitted with pastry tip 1M with the remaining frosting (about 2/3 full) and pipe border around the top of cake. Chill until firm.
- Take cake from fridge and cover the top with a layer of your sprinkle mixture, using a toothpick to push sprinkles in between piping. Once frosting softens again, the sprinkles will adhere to top.
- Serve cake at room temperature, but keep refrigerated if not serving the day it's made.
- For the chocolate cake, I used Cacao Barry Cocoa Powder - Extra Dark.
- For the malted Belgian chocolate frosting I used Callebaut Dark Callets 70.4 %.
- For my sprinkle medley, I used rainbow jimmies, chocolate jimmies, and rainbow non-pareils. But you can try using a pre-mixed medley like Flight of the Unicorn, Bright Skies or Birthday Party!
- To decorate the piped border, I used a medium pastry bag and pastry tip 1M.
- You can make the chocolate cake layers up 2 days ahead, wrapped tight in plastic wrap and stored at room temperature, or up to two weeks ahead wrapped tight and frozen. Thaw in refrigerator and then bring to room temperature.
- Keep decorated cake in refrigerator for up to 2 days, but serve at room temperature.
