Melt dark chocolate in a non-stick pan over low heat, stirring occasionally. Set aside to cool.

Cream together brown sugar & butter using a stand mixer with a paddle attachment on high speed for 4-5 minutes.

Gradually add eggs one at a time, mixing until each is incorporated.

Whisk together flour, salt, baking powder, & cocoa powder in separate bowl.

With the mixer on low, slowly add the dry ingredients to the wet, mixing just until combined.

Stir in melted chocolate and mini chocolate chips until evenly distributed.

Cover the bowl and chill the dough in the refrigerator for at least 1 hour, or up to 24 hours.

Before shaping cookies, preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper.

Form the dough into balls (about 3T / 75g each), roll in granulated sugar, then powdered sugar.

Place on the prepared baking sheet and bake for 20 minutes.

Let cool on the baking sheet for 30-45 minutes before serving.