Jeremy's Peanut Butter Cake with Sour Cream Ganache

Jeremy, aka Cabbage Jello, is having himself another birthday. He is kind of ho-hum about his birthdays, but secretly I think he likes to do something to celebrate the day. At least he likes a peanut butter-chocolate cake on his birthday. I usually bake up a couple of chocolate cakes and frost them with a peanut butter-cream cheese frosting, but this year I wanted to shake things up.

Peanut butter CAKE and chocolate frosting! I know, crazy!

September 20, 2011
Name of Cake: A Cake for a Cabbage
Occasion: Cabbage's Birthday
Constituents: two 6x1.5 inch peanut butter cakes filled and frosted with sour cream ganache

For some reason, in the last few years poor Cabbage's birthday falls right at a time when I am super busy. This means that I don't have much time to do a lot of fun stuff with his cake, like frost it in peanut butter frosting then glaze it in ganache, or make the peanut butter ganache from Rose's Heavenly Cakes. It means that I have time to defrost a tub of sour cream ganache and fill and frost with that. Not that I think it won't pair well, I just hope it won't overpower the peanut butter cakes. Cabbage likes at least a 50/50 balance of peanut butter to chocolate, and would prefer to tip the balance in favor of peanut butter.

I did a quick search around the internet to see if there were any peanut butter cakes I would want to try. The first link I clicked on, Eat, Live, Run had a nice one layer cake that she said was really light and fluffy. Further tooling around the internet found this same recipe repeated everywhere, and I discovered it originally came from Bon Appetit in 2005.

The original recipe was a three layer 9x1.5 inch cake, filled with a peanut butter-chocolate ganache type goo and frosted with a cream cheese frosting and topped with butterfinger bits. Holy cow, people. Can we say too much? However, I was pleased to see the recipe used natural peanut butter instead of that hydrogenated sugared crap most recipes lean on.

I converted the original recipe to grams (OMG why can't the baking world please just accept the metric system) and cut it in thirds for two 6 inch cakes. I subbed light muscovado for golden brown sugar and scaled it back so that it was equal weight with the flour. I rounded down the egg to one, and increased the leavening to a total of 3/4 teaspoon.

In hindsight, I should have remembered that I have 2 inch pans and if you're only stacking two layers, two inch high cakes look better. I would have cut the recipe into half instead of thirds. As it is, the little cake layers look short. But they do smell peanut buttery, like a peanut butter cookie.

The mixing of the cake is really simple: butter and peanut butter are beat until light, the sugar is creamed with the butter, the eggs are added in, and the dry ingredients are alternated with the buttermilk.

The cake itself was light and fluffy, as promised. The peanut butter flavor was present, and delicious. Sadly, as I feared, the sour cream ganache overpowered the cake. Next time, and there will be a next time, I will think about RHC's peanut buttercream as frosting, and maybe a light whipped ganache as filling, or glaze the cake in the lacquer glaze. And maybe jam as the filling. So many options! All in all, this cake is a peanut buttery winner.

Jeremy's Peanut Butter Birthday Cake
adapted from Bon Appetit's Chocolate-Peanut Butter Cake with Cream Cheese and Butterfinger Frosting
makes two 6x1.5 inch cakes

• 121g bleached all-purpose flour
  
• 1/3 tsp non-aluminum baking powder
  
• 1/3 tsp baking soda
  
• pinch sea salt
  
• 47g unsalted butter, room temperature
  
• 2.5 tbsp natural peanut butter, preferably salted and crunchy
  
• 121g light muscovado sugar (light brown sugar is an ok substitute)
  
• 1 large egg, room temperature
  
• 1/3 tsp vanilla
  
• 81g buttermilk, room temperature

Preheat the oven to 350°F, place a rack in the bottom third of the oven.
Prep the cake pans: grease the bottoms of two 6x1.5 or two 6x2 pans, line the bottoms with parchment rounds, and grease and flour the pans.

In a small bowl, whisk together the flour, baking powder and soda, and salt. Set aside.

In another medium bowl, beat the butter and peanut butter together until light. Beat in the sugar, then the egg, then the vanilla. On low speed, or by hand, mix in the dry ingredients in four parts alternating with the buttermilk in three parts.

Divide the batter between the two pans, even out the tops with an offset spatula, and bake for about 20 minutes, or until a cake tester inserted in the center of the cake comes out clean. Cool on racks for 10 minutes, then turn out the cakes, reinvert so that the tops are up, and let cool completely.

Fill and frost as you like, but too much chocolate ganache will push the peanut butter off the stage and steal the show.