I'm a firm believer that every birthday party should be celebrated with a birthday cake (or at least a birthday dessert). Maybe I use that as an excuse to bake a cake for friends' birthdays, but we all benefit in the end, right?
I haven't been able to stop thinking about this fudgy chocolate-peanut cake since I originally spotted it here, so I made it for a friend's birthday this weekend. It was perfect. I altered it slightly from the original Smitten Kitchen recipe, but it came out so beautifully. The ganache you pour on top of the cake sets up smooth and glossy, giving a "wow, this is homemade?" appearance even though the cake is not actually more difficult to make than any other layer cake.
The original recipe notes say that it serves more than the projected 12 to 16 people because you should serve it in the thinnest slices possible; however, I brought this cake along to dinner at a restaurant and they cut it up to serve all 15 of us, with no leftover cake. Now, I have a sneaking suspicion that they may have cut an extra slice or two for themselves in the back (not that I would blame them), but I suppose that I only suspect that because I wanted more cake. (They did not serve it in the thinnest slices possible so I have no evidence for that basis of that suspicion.)
As for the size recommendation for cutting pieces: while this cake is fudgy, it is not so intensely rich that eating a big piece will overwhelm you. Trust me. : )
Adapted from Smitten Kitchen.
2 cups all-purpose flour2 ½ cups sugar¾ cup unsweetened cocoa powder, preferably Dutch process (I always use Hershey’s Special Dark Cocoa Powder)2 teaspoons baking soda1 teaspoon salt1 cup neutral vegetable oil1 cup (8 ounces) sour cream1 ½ cups coffee (I used a 10-ounce Keurig cup of coffee and added another 2 ounces of water to get 1 ½ cups of liquid total)2 tablespoons distilled white vinegar1 teaspoon vanilla extract2 eggs
peanut butter-cream cheese frosting
10 ounces cream cheese, softened1 stick butter, softened5 cups powdered sugar, sifted⅔ cup smooth peanut butter (I prefer to use Jif Creamy Reduced Fat Peanut Butter because it has a better texture and flavor than their regular peanut butter)
chocolate-peanut butter ganache
8 ounces semisweet chocolate (I used 8 ounces of Ghiradelli semi-sweet chocolate chips)3 tablespoons smooth peanut butter (Again, I prefer to use Jif Creamy Reduced Fat Peanut Butter)2 tablespoons light corn syrup½ cup half-and-half
- Make the cake: Prepare three 9-inch round cake pans first by softening about 2 tablespoons of butter and buttering all sides of each cake pan. Trace the cake pans onto parchment paper and cut out the circles to line each cake pan. Butter the parchment paper in each cake pan after lining the cake pans. Sift together the flour, sugar, cocoa powder, baking soda, and salt. Add the sour cream and vegetable oil to the dry ingredients and mix until combined. Slowly pour in the coffee a little at a time, stirring until a smooth mixture forms. After the coffee and other ingredients are smoothly combined, stir in the vinegar and vanilla. Then, whisk in the eggs. Divide the batter evenly between the three 9-inch round cake pans. Bake at 350 degrees F for 25 to 30 minutes, or until a cake tester or toothpick comes out clean. I have neither toothpicks or cake testers on hand, so I always use a very sharp knife to test my cakes. When the cakes are finished, let them cool in their pans for 20 minutes. As you remove them from the pans, remove the parchment paper and set them with the uneven side up on a plate or cookie sheet that will fit in your freezer. Do not stack them. Freeze for 20 to 30 minutes, or until firm. Before assembling the cake, use a cake leveler or a long serrated bread knife to flatten the top of each cake.
- Make the peanut butter frosting: With a hand- or stand-mixer, beat together the softened cream cheese and the butter until smooth. Slowly beat in the powdered sugar, one cup at a time. When the frosting is smooth, beat in the peanut butter.
- Make the chocolate-peanut butter ganache: In a double boiler, melt together the semi-sweet chocolate, smooth peanut butter, and light corn syrup until smooth, stirring constantly while melting. When the mixture is smooth, remove it from the heat and whisk in the half-and-half. Use while warm.
- To assemble the cake: Remove cake from the freezer for assembly. Stack the cakes, layering them with a thick layer of frosting in between each layer. Using as small amount of frosting possible, ice the outside of your cake with a thin layer of frosting for a "crumb coat" on the outside of your cake. Refrigerate for 15 minutes or until the crumb coat is "set." Use the rest of the frosting and thickly layer it over the cake (to cover any ugly crumb-filled icing spots on your cake, of course!). To get the frosting very smooth, use an offset spatula (example: Offset Handle Icing Spatulas) and run it under very hot water before smoothing the icing. Continue to run it under hot water and smooth the cake's frosting until the frosting is as smooth as you can get. Refrigerate the cake with the peanut butter frosting for at least an hour or until ready to make the ganache. When ready, pour the warm ganache over the top. If it doesn't run to the sides by itself, use your offset spatula to push it to the edges of the cake, where it should roll over in big drops like you see in the pictures. Refrigerate until set or until ready to serve.
- Serving: Remove the cake 1 hour before serving to let it come towards room temperature before serving.
Notes: I made the amount of icing listed here; however, if I had any issues with my cakes falling apart, I would have had to make extra icing to hide the ugly parts. In the future, I will one-and-a-half times the recipe for the peanut butter frosting just for good measure. I'm sure I could find space for it on the cake if I made extra, and, if I couldn't fit it all on the cake, I'm sure I could find extra space for it in my fridge to eat by the spoonful later.