Chocolate Peanut Butter Fun Cake

This cake is so easy and so yummy too. The peanut butter buttercream frosting can also be used for frosting cupcakes and whatnot. Really delicious =)

-Chocolate Cake-
Ingredients:

Nonstick vegetable oil spray
1 1/4 cups all-purpose flour
1 cup sugar
3/4 cup natural unsweetened cocoa powder
1 1/2 teaspoons kosher salt
1 teaspoon baking soda
1/4 cup vegetable oil
1 1/4 cup water
1 teaspoon vanilla extract
1/2 cup finely chopped semisweet or bittersweet chocolate (3 1/2 ounces)

Instructions:

1. Preheat oven to 350°F. Coat bottom and sides of 8x8x2 pan with nonstick spray; line bottom of pan with parchment paper or foil.
2. Whisk flour, sugar, cocoa powder, salt, and baking soda in a large bowl.
3. Add oil, vanilla, and water; whisk until smooth.
4. Fold in chopped chocolate.
5. Scrape into prepared pan; smooth top. Bake until a toothpick comes out clean when inserted into center, 35–40 minutes. Let cool completely in pan on a wire rack.

-Peanut Butter Buttercream-
Ingredients:

1/2 cup sugar
1/4 cup egg whites (from about 2 large eggs)
1 1/2 teaspoons vanilla extract
1/4 cup creamy peanut butter
6 tablespoons (3/4 stick) chilled unsalted butter, cut into 1/4-inch cubes
Kosher salt
1/4 cup chopped semisweet or bittersweet chocolate (about 1 3/4 ounces)
1/4 cup chopped unsalted, dry-roasted peanuts
 
Instructions:

1. Combine sugar and egg whites in a medium metal bowl set over a saucepan of simmering water. Whisk constantly until sugar dissolves and mixture is hot to the touch, 3–4 minutes. 
2. Remove from heat; using an electric mixer, beat on high speed until cool and thick, 5–6 minutes. Beat in vanilla, then peanut butter. With mixer running, add butter a few pieces at a time, beating to blend between additions. Season with salt. 
3. Run a thin knife around pan to release cake. Invert cake onto a serving plate. Spread peanut butter buttercream over top. Garnish with chopped chocolate and peanuts. DO AHEAD: Can be made 1 day ahead. Store airtight at room temperature.
4. Cut into 2-inch squares. Chill in refrigerator.   

Original Recipe from: http://www.bonappetit.com/recipes/2012/03/chocolate-peanut-butter-fun-cake