Preheat the oven to 325ºF. Line 24 muffin tins with cupcake liners.

In the bowl of a mixer, combine all of the cupcake ingredients and mix on low until combined. Turn the speed up to medium and beat for 2 minutes.

Fill each cupcake liner 2/3 full of batter. Bake until a toothpick inserted in the center comes out clean, about 25 minutes. Cool for 10 minutes, then remove to a cooling rack to cool completely.

With a mixer, beat the butter until light and fluffy. Beat in the vanilla. Add in the powdered sugar, 1/2 cup at a time. Beat for 2-3 minutes, until light and fluffy. Add in the milk, 1 teaspoon at a time, until you reach your desired consistency.

Reserve about 1/2 cup of the buttercream. Place the remaining buttercream in a piping bag fitted with a decorative tip. Pipe the buttercream onto the cooled cupcakes, then add sprinkles, if desired.

Tint the reserved buttercream orange or yellow. Place in a piping bag fitted with a small round tip. Place a peanut butter cup upside down on the bottom (chocolate) side of each of the fudge striped cookies. Pipe the frosting around the base of the peanut butter cup to hold it in place. Pipe a buckle on the peanut butter cup.

Place one cookie hat on top of each cupcake.