Peanut Butter Cake with Dark Chocolate Buttercream
Oh, Halloween. This has never really been a favorite holiday of mine. As a kid, there was always something special about Halloween, mostly because schools made such a big deal out of it. Halloween parades, costume parties, games... I think back on all the costumes I've worn over the years, and I think my mother deserves a round of applause for all she's crafted for me. The poodle costume: black leotard, pink tights and "custom" poodle-like fabric sewn and cut with velcro attachments for my wrists and ankles. Little Red Riding Hood: a red cape and a basket filled with morning glory muffins my mom baked herself. One year, my best friend and I went as salt and pepper shakers (which my mom helped create, of course). As one of the elderly women in our neighborhood opened the door to hand us candy, she stared at our costumes, totally perplexed, and then asked, "Postscript?" We then realized we were standing as P and S, not S and P, and we learned very quickly how much that threw people off. Another wonderful memory is the lollipop costume: a massive slice of poster board cut into a gigantic circle, covered in colorful saran wrap and somehow attached to my head. I had to walk sideways through door frames, and our dog ran whimpering into a corner when she saw me wobbling down the stairs. Honestly, Halloween was a great time as a kid, and then when you get older it somehow just starts to get progressively worse. You know what I'm talking about.
Unless, of course, you decide not to attend any Halloween parties and bake a cake and hang out with your nieces instead.
Which is exactly what I'd rather do, obviously. Especially when we have the spookiest, darkest chocolate peanut butter cake to share. YUM. We've got 4 layers of a decadent peanut butter cake, filled with chocolate buttercream (and a little bit of peanut butter in between) and finished off with peanut butter ganache. What makes it ultra spooky is due to a few important factors -- the first is black cocoa, which sounds deviant, and in a way it is. It's a little hard to find, but I ordered mine from King Arthur Flour, and it is everything I thought it would be and more. I used 1/2 cup of the black cocoa in this recipe, and then used 1/4 cup natural cocoa powder for the remainder. It is very strong, but that's what I wanted the buttercream to be. If you're looking for a more mild-flavored chocolate frosting, only use 1/4 cup black cocoa or 2-3 tablespoons. The second spooky factor here is black food coloring gel. I use Americolor (pretty much for all food coloring because it's just better and it doesn't taint the flavor of your treat), and although you may be tempted to keep adding more and more black coloring - STOP, and let the buttercream sit for 15-20 minutes. The color develops over time, so take a few breaks in between frosting and check back in with the color!
Our final and most important spooky element is, of course, sprinkles. I am such a sprinkle addict. Which is why I regularly check Sweetapolita for new sprinkle mixes, as well as Sprinkle Pop Shop, which is where I found these monster mashup sprinkles. They are so much fun!
Of course, that peanut butter ganache drip helps set the vibe too. Be safe out there tonight and be sure to eat plenty of sweets!
Chocolate Peanut Butter Cake
Prep time: 25 minutes | Bake time: 25 minutes | Decorating: 45 minutes - 1 hour
For the peanut butter cakes:
2 1/4 cups all-purpose flour
1 tsp baking soda
1 tsp baking powder
1/2 teaspoon salt
1 cup unsalted butter, softened
1/2 cup creamy peanut butter
3/4 cup sugar
1/2 cup brown sugar
1 tsp vanilla extract
1 1/4 cup buttermilk
For the dark chocolate buttercream:
2 cups unsalted butter, softened
4 cups powdered sugar
1/2 cup black cocoa powder
1/4 cup natural cocoa powder
1/2 cup hot water
1/2 cup sour cream
2 teaspoons vanilla extract
5 oz dark chocolate, melted
Large pinch of salt
Black food coloring, preferably gel
1 cup peanut butter, for filling
For the peanut butter ganache:
1 cup peanut butter chips
1/2 cup heavy cream
Preheat oven to 350 F. Spray 4 6-inch cake pans with cooking spray, set aside. (You can bake this cake in 3 8-inch cake pans or 2 9-inch cake pans, but your bake time will be slightly longer.) In a medium bowl, whisk together flour, baking soda, baking powder & salt.
In the bowl of a stand mixer fitted with the paddle attachment, cream butter on medium speed until pale and creamy. Add peanut butter and mix until combined. Add sugars, vanilla and eggs, beat until combined. Scrape down the sides of the bowl. Add half the flour mixture to the batter, then half the buttermilk. Mix until combined, then repeat with remaining flour and buttermilk. Mix until just combined, then evenly divide batter among the 4 pans. Bake at 350 for 25 minutes, until a toothpick inserted in the center comes out clean.
Allow cakes to cool in pans for 5-10 minutes, then remove from pans and allow to completely cool on a wire rack. If you have extra time when your cakes are cool and you are preparing your frosting, wrap each layer in plastic wrap and place in the freezer until it's time to frost.
While the cakes are cooling, make the chocolate buttercream: in the bowl of a stand mixer fitted with the paddle attachment, beat butter on medium speed until pale and creamy, about 5 minutes. In a separate bowl, whisk powdered sugar and cocoa powders until combined. Add to the butter and beat until smooth. With the mixer running on low speed, slowly add the hot water, sour cream, vanilla and melted chocolate. Beat until combined and add salt to taste. Add black food coloring gradually, starting with about a teaspoon. Mix until combined, and allow to rest for 15-20 minutes. Add additional coloring as needed.
Once cakes are cool, it's time to frost! Using a piping bag with the end snipped (or a large round tip), pipe the frosting on the first layer of the cake, leaving a small circle empty in the middle (I like to use the layer with the smoothest/flattest bottom, or if you have an ugly duckling cake and the middle is sunken, use this as your bottom layer). Spread 1/4 cup of peanut butter in the open circle. Carefully top with your second cake layer, and repeat with remaining layers until you reach the top. Using an offset spatula, generously coat the cake with chocolate frosting and use a bench scraper to remove excess. Place the cake in the fridge while you prepare the peanut butter ganache.
In a small saucepan over low heat, combine cream and peanut butter chips and stir until fully melted and smooth. Allow to cool before transferring to a squeeze bottle, or just use a spoon for the drip.
Remove cake from the fridge and finish off with more chocolate frosting, ensuring the bottom is filled. Use a bench scraper to smooth edges. If you're adding sprinkles to the bottom of your cake, do this now - I found better luck just "throwing" sprinkles at the cake. They stuck better without smearing frosting.
With a small spoon or a squeeze bottle, drip small amounts of the peanut butter ganache close to the edge, allowing the ganache to fall down the cake. Pour the rest of the ganache on the top of the cake and spread with an offset spatula.
If desired, pipe extra chocolate frosting along the edges and the center of the cake, and top with more sprinkles.
Allow the cake to rest in the fridge until ready to serve!