The Chocolate Peanut Butter Cake: three layers of awesome

In my last post, I mentioned that I promised my friend Anna that I would make her a cake to celebrate when her website reached 100 followers.  That fateful day came last week and she got busy with her 100 Followers Contest and I got busy planning what kind of cake to make.

My first thought was to recreate the grasshopper cake, but the chocolate-mint combo was rejected and I needed somewhat of a challenge anyway.  I decided to take the theory of the grasshopper cake (three layers, filled with two fillings each), and run with it in full Peanut Butter style.  What resulted was pure peanut butter heaven.

I began with the recipe for the Chocolate Mayonnaise Cake from this month's issue of Bon Appetite.  I know, it sounds disgusting, but the mayonnaise replaces any other fat in the cake and makes it extra moist.  I have never had from-scratch cakes turn out of the pan so well.

I then made a peanut butter buttercream frosting from Cooks Illustrated (this is a subscription website, recipe below) that knocked my socks off.  I didn't actually have to add the heavy cream, but I did have to bulk it up a little, so after I had made the original recipe, I added another big scoopful of peanut butter and another 1/2 cup or so of powdered sugar.  I am not a big sweets person, and my mother doesn't even like peanut butter, but we were both doing our best not to eat this straight from the bowl. 

The Peanut Butter Ganache was a mix of a bunch of recipes, the grasshopper cake one from He-eats (though without the mint flavoring) and a few found randomly online.  I basically made a standard ganache recipe and added peanut butter.  (I'm not sure who to credit here, it's driving my librarian sensibilities crazy)

Assembling the cake was easy-as-pie, and although it might not be the prettiest cake I've ever made, I have no doubt that it will blow me away taste-wise.  My only regret is that we're busting into it tonight with friends, one of whom is allergic to chocolate.  It's just so sad.  I'm bringing her the leftover buttercream though, that might help ease some of the pain.

Oh, by the way, in order to see what ingredients I was in need of, I measured everything out before beginning the cooking- what a difference that made!  It was like half my clean up was done because all the ingredients were already put away.  And, as a bonus, the only thing I needed to buy was full-fat mayonnaise (blech), one of the benefits to  doing my baking at mom's (the others being a bigger kitchen and an oven that stays on for the whole time, oh, and it's clean).

I'll post more pics with flavor reviews tomorrow!



RECIPES

Mayonnaise Chocolate Cake
(Bon Appetite, April 2010)

Ingredients:

• 2 ounces bittersweet chocolate (do not exceed 61% cacao), chopped
• 2/3 cup unsweetened cocoa powder
• 1 3/4 cups boiling water
• 2 3/4 cups all purpose flour
• 1 1/4 teaspoons baking soda
• 1/4 teaspoon baking powder
• 1 cup sugar
• 1 cup (packed) dark brown sugar
• 1 1/3 cups mayonnaise (do not use reduced-fat or fat-free)
• 2 large eggs
• 1 teaspoon vanilla extract

Preparation:
Preheat oven to 350°F. Butter and flour three 8-inch-diameter cake pans with 1 1/2-inch-high sides. Combine chopped chocolate and cocoa powder in medium metal bowl. Add 1 3/4 cups boiling water and whisk until chocolate is melted and mixture is smooth.

Sift flour, baking soda, and baking powder into another medium bowl.Using electric mixer, beat both sugars and mayonnaise in large bowl until well blended, 2 to 3 minutes. Add eggs 1 at a time, beating until well blended after each addition. Beat in vanilla. Add flour mixture in 4 additions alternately with chocolate mixture in 3 additions, beating until blended after each addition and occasionally scraping down sides of bowl. Divide batter among prepared cake pans (about 2 1/3 cups for each).

Bake cakes until tester inserted into center comes out clean, 30 to 32 minutes. Cool cakes in pans on racks 20 minutes. Run small knife around sides of cakes to loosen. Carefully invert cakes onto racks and let cool completely.

Peanut Butter Buttercream 

(Cooks Illustrated, March 2005)

Ingredients

8	tablespoons unsalted butter, softened
1/2	cup smooth peanut butter (don't use old-fashioned or natural brand)
3/4	cups confectioners' sugar
	Pinch table salt
1/2	teaspoon vanilla extract
1	tablespoon heavy cream

Instructions: 

In standing mixer fitted with whisk attachment, beat butter and peanut butter at medium-high speed until smooth, about 20 seconds. Add confectioners' sugar and salt; beat at medium-low speed until most of the sugar is moistened, about 45 seconds. Scrape down bowl and beat at medium speed until mixture is fully combined, about 15 seconds; scrape bowl, add vanilla and heavy cream, and beat at medium speed until incorporated, about 10 seconds, then increase speed to medium-high and beat until light and fluffy, about 4 minutes, scraping down bowl once or twice.

Ganache 
(??)

Ingredients:
5 oz dark chocolate, chopped
1/4 C smooth peanut butter
1/2 C heavy cream
1/2 t vanilla


Instructions:
Put chopped chocolate and peanut butter in a medium metal bowl and put aside.
In a small saucepan, heat cream and vanilla until reaches a simmer.
Pour liquid mixture over chocolate and peanut butter and let sit 2-3 minutes.
Whisk until smooth and all the chocolate is melted.

 Cake Assembly:

To assemble the cake, place the bottom layer on to serving dish.  Cover top of layer with buttercream.  Place in refrigerator for 1-2 minutes to firm (this part is most only important on the top layer).  Cover with a layer of ganache.  Repeat with middle layer (cake-buttercream-fridge-ganache).  Put on top layer and over with buttercream.  This time, place it in the fridge for a few minutes to make sure the buttercream is really pretty solid (3-4 minutes).  Then cover top and sides with ganache.