01 -
Melt the butter and chocolate chips together in a microwave-safe bowl in 30-second bursts, stirring between each, until smooth. Let cool 5 minutes.
02 -
Whisk the granulated sugar, egg, and vanilla into the cooled chocolate mixture. Fold in the flour, cocoa powder, baking powder, and salt until just combined.
03 -
Beat the softened butter, peanut butter, and brown sugar until light and fluffy. Add the egg and vanilla, then mix in the flour, baking soda, and salt.
04 -
Scoop 1 heaped tablespoon of brownie dough and 1 heaped tablespoon of peanut butter dough. Press them together gently.
05 -
Place on a lined baking sheet. Drizzle a small dot of peanut butter on top and drag a toothpick through in a figure-eight motion once or twice, leaving distinct marbling.
06 -
Freeze the shaped cookies on the pan for 15 minutes while the oven preheats to 350 degrees F.
07 -
Bake for 10-12 minutes until the edges are set and the centers look slightly underdone. Cool on the pan for 5 minutes, then transfer to a wire rack.