Melt together your butter and chocolate chips in a small sauce pan over medium heat.

Allow chocolate to cool for 15 minutes.

In a large bowl combine your dry ingredients (Your flour, cocoa powder, baking powder, and salt) Set aside.

In a large mixing bowl cream together your brown sugar, eggs and vanilla until smooth.

Add your slightly cooled, melted chocolate mixture to your egg mixture and stir until combined.

Slowly add in your dry ingredients while stirring until mixed.

Cover your bowl tightly with plastic wrap and refrigerate for 1-2 hours (The dough is like a thick cake batter before refrigerated, so you'll need it to firm up a good amount).

Preheat your oven to 325 degrees.

Roll your dough into 1 1/2 -2 inch cookie dough balls and place on a baking sheet lined with parchment paper or a silicone liner.

Bake for 10 minutes, until cookies start to crack.

Meanwhile, cut your marshmallows in half and cut your chocolate into 1/2 inch pieces (I cut each piece from the bar into 3 pieces)

Remove from oven and top each cookie with a piece of chocolate and marshmallow and cook for another 3-4 minutes.

Sprinkle grated chocolate over the top of your marshmallows if desired.