Preheat your oven to 350°F (175°C). This ensures that your cookies bake evenly and develop that perfect golden-brown color.
In a large mixing bowl, beat the 1 cup of unsalted butter and 1 cup of sugar together with an electric mixer until the mixture is light and fluffy, about 3-4 minutes.
Add the 2 large eggs one at a time, mixing well after each addition to incorporate air into the batter for a lighter cookie.
In a separate bowl, whisk together 1 cup of dark cocoa powder, 2 1/2 cups of all-purpose flour, 1 tsp coarse salt, and 1 tsp baking powder. Gradually add this dry mixture to the wet ingredients, mixing until just combined. Avoid overmixing.
Gently fold in 1 cup of peanut butter chips and 1 cup of chocolate chips until evenly distributed throughout the dough.
Using a cookie scoop or tablespoon, drop rounded balls of dough onto prepared baking sheets, leaving space between each cookie. Bake in the preheated oven for 10-12 minutes, until edges are set and tops appear slightly underbaked.
Remove cookies from the oven and allow them to cool on the baking sheet for about 5 minutes before transferring to a cooling rack to cool completely.