Preheat the oven to 350°F (175°C) and grease a 9x13 inch baking dish.

In a large saucepan, melt the butter over medium heat.

Once melted, remove from heat and stir in granulated and brown sugars until well blended.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Sift together the flour, cocoa powder, baking powder, and salt in a separate bowl.

Gradually add the dry mixture to the wet ingredients, stirring until just combined.

Fold in the chocolate chips using a spatula.

Pour the batter into the prepared baking dish and spread it evenly.

Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.

Let the brownies cool in the pan on a wire rack for at least 15 minutes before cutting into squares.