Preheat oven to 350°F (175°C) and line a baking sheet with parchment. Melt chocolate chips and butter in a microwave-safe bowl in 30-second intervals, stirring until smooth.
In a large bowl, beat granulated sugar, brown sugar, eggs, and vanilla for 2–3 minutes until fluffy. Stir in the melted chocolate mixture until combined.
In a separate bowl, whisk together flour, cocoa powder, baking powder, and salt. Gradually mix dry ingredients into the wet mixture until a soft dough forms.
In a small bowl, mix peanut butter, powdered sugar, melted butter, and vanilla until smooth and thick.
Scoop 2 tablespoons of dough per cookie onto the baking sheet, spaced 2 inches apart. Drop 1 teaspoon of peanut butter mixture on top of each. Use a toothpick or knife tip to gently swirl the peanut butter into the dough.
Bake for 10–12 minutes, until edges are set and centers are soft and puffed. Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.