In a mixing bowl, beat together creamy peanut butter, softened butter, and brown sugar until light and fluffy, about 2-3 minutes. Add in egg and vanilla extract, mixing until well combined.

In a separate bowl, whisk together all-purpose flour, baking soda, and a pinch of salt, then gradually fold this dry mixture into the wet ingredients until just combined.

In another bowl, combine melted butter and white sugar, whisking until smooth. Stir in cocoa powder until fully incorporated.

Add in egg and vanilla extract, then fold in all-purpose flour, baking powder, and a pinch of salt, along with chocolate chips.

Cover both doughs with plastic wrap and refrigerate for 30 minutes.

Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.

Using a cookie scoop, portion out 1-2 tablespoons of each dough and place them side by side on the prepared baking sheet.

Gently swirl the two doughs together with a toothpick or skewer.

Bake for 9-11 minutes until edges are set but the center remains soft.

Allow cookies to cool on the baking sheet for 5-10 minutes before transferring to a wire rack.