Instructions

PEANUT BUTTER CAKE

1. Adjust one oven rack to the upper middle position and adjust the second oven rack to the lower middle position and heat oven to 350 degrees. Line 2 12-cup and 1 6-cup cupcake pans with cupcake liners and set aside.
   
2. In a large bowl, add the flour, baking powder and salt and whisk to combine.
3. In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, granulated sugar, brown sugar and peanut butter until fluffy, about 5 minutes.
   
4. Add sour cream and vanilla extract and mix until combined. Add the eggs one at a time mixing until just combined, scraping down the sides of the bowl as needed.
5. In a 1 cup liquid measuring cup, combine the milk and water.
6. Add half of the dry ingredients in to the mixer bowl with the butter mixture and mix until combined. Add the milk mixture and mix on low speed to combine. Add the remaining dry ingredients and mix on low speed until just combined. Using a rubber spatula, give the batter a few stirs by hand and divide among the prepared cupcake pans.
   
7. Bake cakes for 15 to 20 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs attached, rotating the pans about halfway through baking.
   
8. Let the cupcakes cool in their pan for 5 minutes on cooling racks. Then, invert cakes onto cooling rack to cool completely.

PEANUT BUTTER CREAM FILLING

1. In the bowl of a stand mixer, fitted with the paddle attachment, mix the butter, peanut butter, honey, vanilla and salt on low speed to combine. Add the powdered sugar a little at a time. Once all the powdered sugar has been incorporated, increase the mixer speed to medium speed and beat until the cream is light and airy, about 5 minutes, scraping down the sides of the bowl as needed.
   

PEANUT BUTTER SWISS MERINGUE BUTTERCREAM

1. In the bowl of a stand mixer, add the egg whites and sugar whisking to combine. Fill a medium-sized saucepan with a few inches of water and bring to a simmer over medium-high heat. Place the mixer bowl with the egg white mixture on top, creating a double boiler. Be sure the bottom of the mixer bowl does not touch the water.
2. Attach a candy thermometer to the bowl and bring mixture to 160 degrees, whisking occasionally. Once the mixture reaches 160 degrees, carefully attach it to the stand mixer.
3. With the whisk attachment attached, beat the egg white mixture on high speed for 10 minutes until the mixture holds medium-stiff peaks. Scrape down the sides of the mixer bowl and attach the paddle attachment to the mixer.
   
4. With the mixer on low speed, add the butter one tablespoon at a time, then add the vanilla extract. Add in the peanut butter and mix to combine. Once combined, increase the mixer speed to medium-high and beat until the buttercream is combined and smooth, about 3 minutes.

ASSEMBLE

1. With a small knife, cut a cone out of the middle section of each cupcake to make room for the Peanut Butter Filling. Cut the cone of cake and toss out, but save the flat circular top.
2. Fill each cupcake with about 1/2 tablespoon of Peanut Butter Filling. Place the circular piece of cake on top.
   
3. Fit a piping bag with piping tip #827 and fill the bag with Swiss Meringue Peanut Butter Buttercream. Pipe swirls on top of each cupcake, then place a peanut butter sandwich cookie on top of each cupcake.