Step 1

Preheat oven to 350°F. Line an 8-inch square baking dish with aluminum foil, leaving some overhang for easy removal. Spray with nonstick cooking spray and set aside.

Step 2

In a large mixing bowl, whisk together the melted butter and granulated sugar until well combined. Mix in the eggs and vanilla extract until fully combined.

Step 3

Sift the flour, cocoa powder, and salt into the dry ingredients and mix until just combined, scraping down the sides of the bowl as needed.

Step 4

Pour half of the brownie batter into the prepared baking pan. Place the peanut butter cups on top of the brownie batter, cutting some in half as needed to make them all fit in one even layer.

Step 5

Add the remaining brownie batter on top and spread into one even layer, making sure all of the peanut butter cups are covered.

Step 6

Bake 350°F for 30-35 minutes or until the tops of the brownies look set. Remove from the oven and transfer to a wire rack to cool completely. Slice into 9-12 squares, serve, and enjoy!