Preheat oven to 350 °F (175 °C). Line a 9×13″ baking pan with parchment paper, leaving overhang for easy removal.

In a large bowl, whisk melted butter and sugar until well combined.

Add eggs one at a time, whisking well after each addition. Stir in vanilla extract.

Sift in flour, cocoa powder, salt, and baking powder. Gently fold until just combined—avoid overmixing.

Fold in half of the candy-coated chocolate gems.

Spread batter evenly into prepared pan and sprinkle the remaining gems on top.

Bake for 25–30 minutes, or until edges are set and a toothpick inserted comes out with a few moist crumbs.

Cool completely in the pan on a wire rack. Use parchment overhang to lift brownie slab, then slice into squares.

Store in an airtight container to preserve chewy texture and crunchy candy.