Preheat oven 350 degrees F

In a microwave safe bowl add in the chocolate and butter. Microwave on 30 second intervals, making sure to stir after each time, until melted

To the melted chocolate add in the eggs, sugar, and vanilla. Whisk to combine

To the bowl add in the flour, baking powder, and salt. Stir to combine

Lightly grease an 8×8 baking pan and add in half of the batter

Sprinkle a handful of the mini Reese’s peanut butter cups to the top of the batter and then add the remaining half of the batter mix

Add the peanut butter in smaller dollops to the top of the brownie batter. Using a knife, swirl the peanut butter into the brownie mix. Don’t over swirl! You want to be able to see the peanut butter still

Put it into the preheated oven and bake for 30-35 minutes, or until a tester inserted into the middle comes out clean

Let them cool slightly before taking out, slicing, and serving!