In a large mixing bowl, cream together the creamy peanut butter, softened melted butter, and brown sugar until the mixture is light and fluffy, approximately 3-4 minutes. Add in the egg and vanilla extract, blending just until incorporated.

In a separate bowl, whisk together the all-purpose flour, baking soda, and salt before gradually mixing it into the wet ingredients until just combined.

In another mixing bowl, whisk together the melted butter and white sugar until the mixture is smooth and shiny, about 2 minutes. Stir in the cocoa powder, followed by the egg and vanilla extract, mixing until fully incorporated.

Finally, fold in the flour, baking powder, and salt along with the chocolate chips until just combined, creating a rich brownie batter.

Wrap both doughs in plastic wrap and chill in the refrigerator for about 30 minutes.

Preheat your oven to 350°F (175°C). Once chilled, take cookie scoops of each dough and place them side by side on a parchment-lined baking sheet. Use a toothpick or skewer to gently swirl the cookie doughs together.

Bake for 9-11 minutes. Keep an eye on the cookies; they should have lightly crackly tops and slightly set edges, while the centers remain soft.

Allow to cool on the baking sheet for about 5-10 minutes, then transfer to a wire rack to cool completely.