Preheat oven to 375°F and line cupcake pan with liners and set aside.
In a large mixing bowl or stand mixer fitted with a whisk attachment, combine all of the cupcake ingredients, making sure to scrape down the sides as needed.
Add a scant ¼ cup of batter to each liner so they’re about ¾ full.
Reduce heat to 350°F and bake the cupcakes for about 18 to 20 minutes or until a toothpick inserted in the center of a cupcake comes out clean.
Let the cupcakes sit in the pan for a couple of minutes before transferring to a cooling rack to cool completely before frosting.
Use a cupcake corer to core the cupcakes, fill the holes with mini Reese's Pieces.
Frosting:
While the cupcakes are cooling, prepare the Peanut Butter Frosting as indicated in the recipe instructions.
Pipe frosting onto the cooled cupcakes. Top each cupcake with a Reese's cup.
For added wow, Use a small frosting tip to frost the Reese's cup!