In a microwave safe bowl add the chocolate chips and butter and microwave in 30 second intervals, stirring after each interval, until the chocolate is fully melted. You can also do this over a double boiler if you prefer.
Place the chocolate in a large mixing bowl and let it cool for 5 minutes.
Add the brown sugar and granulated sugar and stir until very well combined.
Add the eggs and vanilla and beat until light and fluffy, about 3 minutes.
Add the flour, cocoa powder, salt, and baking powder and stir to combine. Chill the dough for 30 minutes.
Preheat the oven to 350 degrees F. and line a baking sheet with parchment paper or a baking mat.
After the dough has finished chilling scoop it to 1.5 tablespoon balls and roll them in clean hands to make them very round. Place about 2 inches apart on your prepared tray.
Bake the cookies for 12-13 minutes, the edges will look set.
Remove from the oven and allow to cool on the pan for 5 minutes before transferring the cookies to a wire rack to finish cooling.