Preheat your oven to 350°F (175°C).
In a double boiler or microwave-safe bowl, melt the bittersweet chocolate with the unsalted butter. Stir until smooth and let cool slightly.
Whisk together the all-purpose flour, cocoa powder, baking powder, and salt in a separate bowl.
In a large mixing bowl, beat together the granulated sugar and eggs until pale and fluffy. Stir in the melted chocolate mixture and vanilla extract.
Gradually add the dry ingredients to the wet ingredients, mixing gently until just combined.
Fold in the chocolate chips until evenly distributed.
Using a cookie scoop or spoon, drop rounded tablespoons of dough onto a prepared baking sheet.
Bake for about 10-12 minutes, until edges are set but the center looks slightly underbaked.
Allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack.