Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a mixing bowl, melt the unsalted butter either in the microwave or on the stovetop. Let it cool slightly.
Add the granulated sugar to the melted butter and mix until combined.
Add in the eggs, one at a time, and stir well after each addition. Mix in the vanilla extract.
In another bowl, sift together the all-purpose flour, cocoa powder, salt, and baking powder.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
Fold in the semi-sweet chocolate chips until evenly distributed throughout the dough.
Drop tablespoon-sized portions of the cookie dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 10-12 minutes, or until the edges are set and the tops look slightly cracked.
Remove from the oven and let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.