Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine melted butter, brown sugar, and granulated sugar. Mix well.
Add eggs and vanilla extract to the mixture. Stir until smooth.
In a separate bowl, whisk together flour, cocoa powder, baking powder, and salt.
Gradually add the dry ingredients to the wet mixture. Stir until just combined.
Fold in the chocolate chips.
Drop spoonfuls of dough onto a baking sheet lined with parchment paper.
Bake for 10-12 minutes, or until the edges are set but the centers are still soft.
Allow to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.