Instructions

CUPCAKES

1. Adjust and oven rack to the center of the oven and heat to 350 degrees. Line a cupcake pan with cupcake liners and set aside.
2. In the bowl of a stand mixer, beat the butter and sugar until light and fluffy, about 5 minutes. Add the sour cream and vanilla extract and mix until combined. Add one egg white and mix to combine. Add the remaining 2 egg whites and mix until incorporated.
3. In a large bowl, whisk together the flour, cocoa, baking powder and salt. In a liquid measuring cup, combine the boiling water and espresso powder and stir until the espresso powder has dissolved. Add in the milk and whisk to combine. Add half of the dry ingredients to the batter and mix to combine. Add the wet ingredients and mix to combined. Add the remaining dry ingredients and mix until just combined. Give the batter a few stirs by hand with a rubber spatula.
   
4. Using a 3 tablespoon sized ice cream scoop, scoop out the batter and divide among the prepared cupcake pan. Bake cupcakes for about 15 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs attached. Allow the cupcakes to cool in the pan for 2 minutes, and then invert cupcakes on to a cooling rack to cool completely.

PEANUT BUTTER BUTTERCREAM

1. In the stainless steel bowl of a stand mixer, with the whisk attachment attached, pour the egg whites and cream of tartar in the bowl and mix on low speed until frothy, about 2 to 3 minutes.  Slowly add ¼ cup of the granulated sugar on increase the mixer speed to medium-high. Beat until soft peaks form, about 30 seconds.
2. In a small saucepan, add the remaining 1 ½ cups sugar and water. And stir to combine. Attach a candy thermometer to the saucepan and heat mixture over high heat until it reaches 180 degrees, about 5 minutes. Continue to cook until the syrup reaches 240 degrees, about 2 minutes more.
3. Once the syrup reaches 240 degrees, carefully pour the syrup in the meringue in the mixer bowl, mixing on high speed for about 12 minutes or until the mixer bowl is room temperature. Switch out the whisk attachment for the paddle attachment and mix on low speed adding the butter one piece at a time. Once all the butter has been incorporated, increase the speed to medium and beat until the buttercream is thick and fluffy, about 1 minute. Reduce the speed to low and add the vanilla extract and salt. Add in the peanut butter and mix to combine

ASSEMBLE

1. Divide buttercream between two piping bags, one bag fitted with Ateco #827 tip and the other with a Wilton #21 tip. Pipe swirls on top of the cupcakes with the piping bag fitted with the #827 tip. Pipe all cupcakes, refilling the bag as necessary with more buttercream.
2. Insert a toothpick in the bottom of the chocolate candy before icing the top. Remove the toothpick and ice the top of the chocolate candy with the piping bag fitted with tip #21. Stick the toothpick back into the premade hole and place on top of the iced cupcake. Repeat this process until all the cupcakes have a mini cupcake on top.