Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.

In a small saucepan or microwave-safe bowl, melt the butter with 1/2 cup of the chocolate chips until smooth. Let it cool slightly.

In a large mixing bowl, whisk together the granulated sugar, brown sugar, eggs, and vanilla extract until light and creamy.

Pour in the melted chocolate mixture and stir until well combined.

In another bowl, whisk together the flour, cocoa powder, baking powder, and salt. Gradually add the dry ingredients to the wet mixture and stir until just combined.

Fold in the remaining 1/2 cup of chocolate chips.

Scoop tablespoon-sized portions of dough onto the prepared baking sheets, spacing them about 2 inches apart.

Bake for 9–11 minutes, or until the tops are crackly and the edges are set but the centers are still soft.

Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.