Dark Chocolate Cake with Peanut Butter Frosting

Eli turned 30-something last Sunday. We had a day-long celebration, in spite of his expected I-am-laid-back-I-have-no-preferences assertion that he wanted to do “whatever” to mark being a year older. So I planned everything, and as always, the plans grew until every moment was filled. There were no famous people or crazy activities involved – just family and friends, brunch at Real Food Cafe in Alger Heights, NASCAR and an episode of Top Gear on the big HD flat-screen TV at his parents’ house, his mom’s special East African pork curry for dinner, and of course, cake and ice cream (Hudsonville vanilla, made in a small town just outside Grand Rapids – when it comes to ice cream, at least, Eli is a locavore).

Even before I started thinking about what and who Eli’s birthday would involve, I started thinking about his birthday cake. Making birthday cakes for people is something I’ve been doing, usually upon request, for about 15 years now – ever since I started making wedding cakes – and I wanted this particular cake to be special. It had to be from scratch, and it needed to involve two of his favorite things: chocolate and peanut butter.

After hunting through my cookbooks, I settled on chocolate cake with peanut butter frosting, both variations on recipes in Ina Garten’s Barefoot Contessa at Home. Because I knew I needed enough cake for a crowd, I doubled the recipes and made a 10-inch layer cake rather than the standard 8-inch. It would have easily fed 20 people. As it was, there were a few slices left to enjoy during the coming week.

I was more than happy with the results – the cake is moist but not heavy, the chocolate rich but not too rich. The peanut butter frosting is made lighter by a greater ratio of butter to peanut butter, and was easy to pipe through the tip of a pastry bag. I decorated with Peanut M & M’s, Eli’s favorite candy. It was better than any Reese cup.

What makes the chocolate flavor so perfect is the last-minute addition of hot, freshly brewed coffee. I promise you won’t taste it in the final product. The coffee makes the cocoa flavonoids “pop,” and the flavor becomes richer. Don’t ask me how – it just works. And in spite of Eli’s teasing claim that he could taste the coffee, and that I’d ruined it by telling him there was coffee in the batter, I have a feeling this won’t be the last chocolate cake with peanut butter frosting that shows up for his birthday.

You don’t need anything more than a scoop of vanilla ice cream alongside this, or a glass of cold milk. The recipe below makes two 8-inch round layers, or a 9-inch by 13-inch rectangle.

Dark Chocolate Cake with Peanut Butter Frosting

For the cake:

Preheat the oven to 350 degrees.

Grease the pan(s), and line the bottom with parchment, then grease again.

In a large bowl, sift together:
1-3/4 cups flour
2 cups sugar
3/4 cup cocoa
2 teaspoons baking soda
1 teaspoon baking powder
1 teaspoon salt

In a medium bowl or the bowl of an electric mixer, combine:
1 cup buttermilk
1/2 cup canola oil
2 extra large or 3 large eggs, at room temperature
2 teaspoons vanilla extract

Add the dry ingredients to the wet, and mix well until fully combined. Stir in 1 cup hot, freshly brewed  coffee until just combined. The batter will be quite runny.

Pour into the prepared pan(s) and bake 35-45 minutes, until a toothpick inserted in the center comes out clean. Remove to a rack and cool 30 minutes, then turn out of the pans and finish cooling. The cake should be fairly flat and will not require trimming – just place the layers top side down so that the flattest part is facing up, and frost.

For the frosting:

In the bowl of an electric mixer, beat together:

1 cup creamy peanut butter
1 stick (8 tablespoons) unsalted butter

Add and mix well:

1 teaspoon vanilla extract
1/4 teaspoon salt

Slowly add 1 cup confectioners sugar, a 1/3 cup or so at a time, mixing well after each addition.

With the mixer running on low, slowly pour in 1/3 cup heavy whipping cream. Scrape down the sides of the bowl as needed, and continue to blend all ingredients together on low speed until smooth and creamy. Cover and set aside until cake is completely cool – do not refrigerate, or frosting will sweat.