Creamy Peanut Butter-Filled Devil’s Food Cupcakes with Milk Chocolate Ganache

Makes 12 cupcakes

FOR THE CUPCAKES:

½ cup (1½oz/40g) unsweetened natural cocoa powder, sifted if lumpy

¾ cup (180ml) boiling water

1 cup (4½oz./130g) unbleached all-purpose flour

¾ tsp baking soda

½ tsp table salt

6 tbsp (3oz/85g) unsalted butter, softened

¾ cup (5¼oz/150g) firmly packed light brown sugar

1 whole large egg, at room temperature

1 yolk from a large egg, at room temperature

1 tsp pure vanilla extract

FOR THE FILLING:

1/3 cup (3oz/85g) creamy peanut butter

4 tbsp (2oz/60g) unsalted butter, softened

½ cup (2oz/60g) confectioners’ sugar, sifted if lumpy

FOR THE MILK CHOCOLATE GANACHE:

6oz (170g) milk chocolate, finely chopped

4 tbsp (2oz/60g) unsalted butter, cut into 2 pieces

Pinch of table salt

½ cup (120ml) heavy cream

1/3 cup (15/8 oz/46g) salted peanuts,

coarsely chopped, for garnish

1. Make the cupcakes: Position a rack in the center of the oven and heat the oven to 350°F/180°C/Gas 4). Line 12 regular-sized muffin cups with paper or foil liners. Put the cocoa powder in a small bowl. Pour in the boiling water and whisk until well blended and smooth.

2. Whisk the flour, baking soda, and salt in a small bowl until well blended. Put the butter in the bowl of a stand mixer fitted with the paddle attachment (or in a large bowl using an electric handheld mixer fitted with wire beaters) and beat on medium speed until smooth, about 1 minute. Add the brown sugar and beat on medium-high speed until fluffy and lighter in color, about 2 minutes. Add the egg, yolk, and vanilla and beat until blended. Stop to scrape down the bowl and beater as needed. Add the cocoa mixture and mix until just blended. Using a silicone spatula, fold in the flour mixture.

3. Portion the batter evenly among the prepared muffin cups (a scant ¼ cup/60ml batter per cup will fill them about two-thirds full). Bake until a pick inserted in the center comes out clean, 13 to 15 minutes. Move to a rack and let cool for 15 minutes. Carefully remove the cupcakes from the pan, set them on a rack, and let cool completely.

4. While the cupcakes are cooling, make the filling. Put the peanut butter and butter in the bowl of a stand mixer fitted with the paddle attachment (or in a medium bowl using an electric handheld mixer fitted with wire beaters) and beat on medium speed until well blended and smooth, about 1 minute. Add the confectioners’ sugar and beat on medium speed until well blended and smooth.

5. Make the milk chocolate ganache: Put the chocolate, butter, and salt in a small bowl. Put the cream in a small saucepan, set over medium heat, and bring to a boil (this can also be done in the microwave). Pour over the chocolate mixture and whisk until well blended and smooth. Set aside, stirring occasionally, until thick enough to spread. For faster cooling, set the bowl over a larger bowl filled with ice and a little water, stirring and scraping the sides frequently until chilled and thick enough to spread.

6. To fill the cupcakes, use either the pastry bag method or hulling method. For filling with a pastry bag, fit a bag with a small (¼ inch/ 6 mm) round tip and fill the bag with the filling. Working with one cupcake at a time, insert the tip down into the center of the cupcake and squeeze the bag to insert the filling until the cupcake begins to expand and the filling reaches the top of the cake. If you don’t have a pastry bag, use a small sharp knife to cut a 1-inch (2.5cm) circle in the top center of each cupcake. Continue cutting, on an angle, into the cake until you reach the middle. Carefully pull out the cake center (it will be shaped a bit like a cone), cut off and reserve the top, and snack on the inside. Spoon about 1 tbsp of the filling into each cupcake and replace the tops.

7. Top the filled cupcakes with 1 to 2 tbsp of the ganache. (Any leftover ganache can be warmed and served over ice cream.) Using a small offset spatula, spread the ganache on top of the cupcakes, leaving a border of cake around each one, then sprinkle with the chopped peanuts. Serve immediately; the cupcakes are best served at room temperature.

Make Ahead: The cupcakes can be baked, cooled completely, covered, and stowed at room temperature for up to 1 day before filling and frosting. The filled and frosted cupcakes can be covered and refrigerated for up to 2 days. Bring to room temperature before topping with the peanuts and serving.