In a large mixing bowl, cream together the unsalted butter, granulated sugar, and powdered sugar until light and fluffy, about 3-4 minutes. Add vanilla extract and mix until well combined.

In a separate bowl, whisk together the all-purpose flour, cocoa powder, salt, and baking powder. Gradually add to the butter mixture, stirring gently until just combined.

Fold in chopped pecans or walnuts, or shredded coconut for a nut-free version, until evenly distributed.

Cover the dough with plastic wrap and refrigerate for at least 30 minutes.

Preheat your oven to 350°F (175°C). Scoop about a tablespoon of dough, roll into a ball, indent the center, and place a chocolate chunk inside before sealing.

Roll each ball in powdered sugar and place on a baking tray lined with parchment paper, spacing them 2 inches apart.

Bake the cookies for 10-12 minutes until the edges are firm but centers are still soft.

Cool on the baking tray for about 5 minutes before transferring to a wire rack to cool completely.