Preheat your oven to 350°F (175°C) and grease an 8x8 inch baking pan or line it with parchment paper.

In a medium saucepan, melt the butter over low heat and let it cool slightly. Stir in both sugars until well combined.

Add the eggs one at a time, mixing until glossy.

In a separate bowl, whisk together cocoa powder, flour, baking powder, and salt. Gradually fold this into the wet mixture until just combined.

Mix in chocolate chips and pour the batter into the prepared pan, smoothing the top.

Bake for 25-30 minutes or until a toothpick inserted comes out with moist crumbs attached. Let cool before cutting into squares.