1 3/4 cups all purpose flour
3/4 cup unsweetened cocoa powder
1/2 teaspoon baking powder
1 teaspoon baking soda
1 teaspoon salt
1/2 cup unsalted butter, softened but still cool
2 ounces cream cheese, softened but still cool
1 cup sugar
2/3 c brown sugar
2 large eggs, at room temperature
1 teaspoon vanilla extract
¼ cup sour cream
1 cup buttermilk, at room temperature
1. Preheat oven to 350 degrees. Line two 12-cup muffin tins with cupcake papers. (Alternatively, line one muffin tin with papers and spray one 9 inch round cake pan with cooking spray, line with a parchment round, then butter the parchment.)
2. Sift together the flour, cocoa, baking powder, baking soda, and salt into a medium bowl; set aside.
3. In a large bowl, using a hand or stand mixer, beat butter and cream cheese until well mixed; add sugar and beat until light and fluffy, about three minutes. Beat in eggs, one at a time, then beat in sour cream and vanilla, scraping down the bowl with a spatula as you go. Add one third of the flour mixture to the butter, beat well, then beat in half of the buttermilk. Beat in another third of flour mixture, then second half of buttermilk. End with the last third of the flour, beat until well combined, making sure to scrape down the bowl with a spatula.
4. Using an ice cream scoop, fill cupcake cups with cake batter (they should be 2/3 – 3/4 full). Place muffin tins on the middle rack of a preheated 350 degree oven. Bake for approximately 20-22 minutes for cupcakes (and cake), rotating pans halfway through. Cupcakes are done when a toothpick inserted in the center comes out clean. Be careful not to overbake.
5. Cool the cupcakes in their tins on a wire rack for 10 minutes then remove and allow to cool completely before filling with peanut butter mixture and icing with ganache.
Salted Peanut Butter Filling
5 tablespoons unsalted butter, at room temperature
1 cup peanut butter
1 teaspoon vanilla
1 1/3 cups powdered sugar, sifted
1/2 teaspoon fine sea salt
½ cup heavy cream
Beat butter on medium until smooth. Add peanut butter, salt, and vanilla and beat until just combined. Reduce speed to low and add powdered sugar in 3 additions until well mixed.
Transfer peanut butter filling to a pastry bag fitted with a round tip. Insert tip through the top of each cupcake, poking slightly more than halfway down. Slowly squeeze the bag to fill the cake with the peanut butter mixture. Continue with each additional cupcake until finished. (Alternatively, you can frost the cake/cupcakes with the peanut butter icing and drizzle with the ganache, building up the frosting around the edge to prevent the ganache from running over.)
6 ounces semi-sweet chocolate chips
1 tablespoon light corn syrup
1 tablespoon creamy peanut butter
½ cup heavy cream
½ teaspoon vanilla
coarse or flaky sea salt (such as fleur de sel), for garnish*
Place chocolate chips, peanut butter, and corn syrup in a small bowl. Place sieve over bowl.
Heat heavy cream to a boil (it should look like it's threatening to boil over) in a small saucepan, pour immediately through sieve. Let chocolate sit for one minute, then slowly whisk until all chocolate is melted. Add vanilla and whisk to combine, being careful not to incorporate air into the ganache.
Dip each cupcake in ganache, sprinkle with salt, and allow to set. Refrigerate. When ready to serve, remove cake from fridge 15 minutes prior to serving.
*Note: consume within one day of sprinkling with salt, or leave cakes unsalted if not consuming the same day. The salt may dissolve into the ganache otherwise, which will result in salty ganache (rather than a salty crunch).