1 3/4 cups (350 grams) granulated white sugar
1 3/4 cups (225 grams) all-purpose flour
3/4 cup (75 grams) unsweetened cocoa powder (natural or Dutch-processed), sifted
1 teaspoon (4 grams) baking soda
1 teaspoon (4 grams) baking powder
1/2 teaspoon (2 grams) kosher salt
3 large eggs, at room temperature
1 3/4 cups (420 ml/grams) buttermilk, at room temperature
1/2 cup (120 ml/grams) corn, vegetable, safflower or canola oil
1 1/2 teaspoons (6 grams) pure vanilla extract
8 ounces (240 grams) semi sweet chocolate, finely chopped (I used a chocolate with a 58% cacao content)
1 cup (240 ml/grams) heavy whipping cream (cream with a 35-40% butterfat content)
Peanut Butter Frosting:
3 ounces (85 grams) full fat (regular) cream cheese, at room temperature
1 cup (225 grams) unsalted butter, at room temperature
1/2 cup (60 grams) confectioners (powdered or icing) sugar, sifted
1 teaspoon (4 grams) pure vanilla extract
3/4 cup (185 grams) smooth peanut butter
2 teaspoons (10 grams) molasses (optional)
Chocolate Shavings or Grated Chocolate
Chocolate Cake: Preheat your oven to 350 degrees F (180 degrees C) and place the oven rack in the center of the oven. Butter, or spray with a non stick vegetable spray, two - 8 x 2 inch (20 x 5 cm) round cake pans. Then line the bottoms of the pans with parchment paper.
In the bowl of your electric stand mixer, fitted with the paddle attachment, (or with a hand mixer) beat the sugar, flour, cocoa powder, baking soda, baking powder, and salt until combined.
In another large bowl, whisk together the eggs, buttermilk, oil, and vanilla extract. On low speed, add 1/3 of the wet ingredients to the dry ingredients and beat until the mixture is a thick smooth paste. Add another 1/3 of the wet ingredients and mix, on low speed, until the batter is nice and smooth. At this point, scape down the sides and bottom of your bowl. Finally, add the rest of the wet ingredients and beat until incorporated and you have a smooth batter.
Evenly divide the batter between the two pans (about 670 grams in each pan) and bake for about 35 - 40 minutes or until a toothpick inserted into the center of the cake just comes out clean and the cakes are just starting to pull away from the sides of the pans.
Remove from oven and let cool on a wire rack for about 15-20 minutes. Then remove the cakes from their pans and cool completely on a greased wire rack before frosting. (The unfrosted cakes can be frozen for one month. Defrost in the refrigerator overnight.)
Chocolate Ganache: Place the chopped chocolate in a heatproof bowl. Set aside. Heat the cream in a small saucepan over medium heat. Bring just to a boil. (Can also heat the cream in the microwave, but watch carefully.) Immediately pour the boiling cream over the chocolate and allow to stand, without stirring, for a few minutes. Then, using a heatproof spatula, and starting in the center, stir the chocolate mixture in circles until the chocolate has melted and the ganache is nice and smooth. Immediately cover with plastic wrap, and let sit, at room temperature, until the ganache is of spreading consistency. This can take several hours (I let it sit overnight).
Peanut Butter Frosting: In the bowl of your electric stand mixer, fitted with the paddle attachment (or with a hand mixer), beat the cream cheese and butter, on medium speed, until smooth. Add the remaining ingredients and beat, on medium speed, until light and fluffy. (The frosting can be refrigerated for five days or frozen for about two months. The frosting will have to be brought to room temperature and rewhipped.)
Assemble: Cut the two cake layers in half horizontally (so you will have four layers of cake). Place one cake layer (top of the cake facing up) onto a 9 inch (23 cm) cake circle. Spread with about 1/3 (1/2 cup (160 grams)) of the peanut butter frosting. Place the next cake layer, cut side down, onto the peanut butter frosting and spread with about 1/2 cup (150 grams) of ganache. Top with another layer of cake and spread with another 1/3 (1/2 cup (160 grams)) of the peanut butter frosting. Finally, top with the fourth layer of cake, bottom of the cake facing up, and cover the entire cake with a very thin layer of Ganache (using a scant 1/2 cup (150 grams)) (this is called a crumb coat). Refrigerate the cake for about 30 minutes or until the Ganache has set. Once the Ganache has set, spread the remaining Peanut Butter Frosting on the top of the cake, using a spatula to create a swirl pattern. Place the cake in the refrigerator and chill until the peanut butter frosting is set (about 15 - 30 minutes). Then spread a very thin layer of Ganache on the sides of the cake and, if desired, press chocolate shavings or curls into the Ganache.
The finished cake can be covered and stored in the refrigerator for about three days or frozen (well wrapped) for about one month. (If freezing, defrost in the refrigerator overnight.) Bring the cake to room temperature before serving.
Serves about 12 - 14 people.
This cake is all about peanut butter and chocolate. The cake consists of four layers of a Chocolate Buttermilk Cake that has a deep chocolate flavor and is wonderfully moist and dense. It is filled with alternating layers of a peanut butter frosting and a chocolate ganache. The top of the cake is then frosted with more of the peanut butter frosting and the sides are covered with the rest of the chocolate ganache. I like to decorate the cake with chocolate curls and shavings which makes it quite stunning.
When I took a 'Cake Bases, Creams, and Composition Class' at the San Francisco Baking Institute, this is one of the desserts we made. I think it was my favorite. The chocolate buttermilk cake gets its wonderful deep chocolate flavor from unsweetened cocoa powder. For the cocoa powder you can use natural unsweetened cocoa powder or Dutch-processed (alkalized). (I use Valrhona Dutch processed unsweetened cocoa powder.) Just remember that both the type and brand of unsweetened cocoa powder you use will affect both the taste and color of your chocolate cake.
One of the reasons for the cake's soft and tender texture is that the fat is in liquid form (a flavorless oil). The added benefit of using oil, instead of butter, is that it keeps the cake soft even when refrigerated. As far as the type of oil to use, good choices are vegetable, canola, corn, safflower, or even a light olive oil. Buttermilk is also used in this cake. It has a nice thick creamy texture with a rich tangy buttery taste that makes baked goods tender. You can buy it or make a good substitute. Stir 1 3/4 tablespoons of vinegar or lemon juice into 1 3/4 cups (420 ml/grams) of whole or reduced fat milk. Let stand at room temperature for about 10 minutes before using.
I just love this peanut butter frosting. It has a nice peanut flavor which is enhanced by adding a little molasses to the frosting. Peanut butter is a smooth paste made from roasted peanuts. The peanuts are ground, and then salt, a sweetener, and sometimes a stabilizer (to keep the oil from separating) are added. There are two types of peanut butter, and the one that is labeled "Old-Fashioned" or "Natural" does not contain a stabilizer. For this recipe I prefer to use the type of peanut butter that contains a stabilizer. If you use the natural peanut butter you may find your frosting is a little soft. If that happens you need to either add more butter or sugar to the frosting to make it thick enough to pipe.