Preheat oven to 350°F and line two baking sheets with parchment paper.

Melt 1 1/2 cups chocolate chips and butter together in a microwave-safe bowl, stirring every 30 seconds until smooth. Let cool slightly.

In a large bowl, beat eggs and sugar together until pale and fluffy, about 2 minutes. Stir in the melted chocolate mixture and vanilla extract.

In a separate bowl, whisk together cocoa powder, gluten-free flour, baking powder, and salt. Fold the dry ingredients into the chocolate mixture until just combined.

Stir in remaining 1/2 cup chocolate chips. Drop rounded tablespoons of dough onto prepared baking sheets, spacing them 2 inches apart.

Bake for 10-12 minutes until tops are crackled but centers still look slightly soft. Cool on baking sheet for 5 minutes before transferring to a wire rack.