Preparation Steps

• Preheat oven to 350°F. Prepare a 9-inch cake pan with parchment paper on the bottom and spray on the sides.
• In a medium bowl, combine the all-purpose flour, baking soda, and salt; set aside.
• In a large mixing bowl, cream the butter, peanut butter, granulated sugar, and brown sugar on medium speed until light and fluffy, about 2-3 minutes.
• Add the egg and vanilla extract, mixing until well combined.
• Gradually add the dry ingredients and mix until just combined; do not overmix.
• Fold in the chopped peanut butter cups and chocolate chips evenly into the dough.
• Press the cookie dough evenly into the prepared cake pan and press a few more chocolate chips and/or chopped Reese’s on top if desired.
• Bake for 18-22 minutes or until the edges are golden and the center looks set.
• Allow the cookie cake to cool completely in the pan, then carefully transfer to a serving plate.
• For the buttercream, beat the butter in a large bowl until smooth. Add 1 cup powdered sugar and mix well.
• Add cocoa powder and vanilla extract, mixing until combined. Add heavy cream and mix until smooth.
• Add the remaining powdered sugar and mix until smooth. Add more cream if needed to reach desired consistency.
• Pipe the buttercream around the edges of the cookie cake and garnish with halved Reese’s between each swirl.
• Store the cookie cake in an airtight container at room temperature for up to 2 days, then refrigerate. Serve at room temperature. Best eaten within 4-5 days.