Preheat oven to 350˚F. Line a 9x9-inch baking pan with parchment paper. Spray with nonstick spray and set aside.
In a large bowl, stir melted butter and sugar together. Stir in the eggs and vanilla until well combined.
In a medium bowl, whisk together the flour, cocoa powder, salt and baking powder. Stir into butter mixture, just until combined. Fold in chocolate chips, then gently fold in half of the raspberries.
Pour the batter into an 8×8-inch baking pan lined with parchment paper and smooth out to an even layer.Gently push the remaining raspberries into the batter.
Bake for 35 to 40 minutes, until a toothpick inserted in the center comes out with just a few moist crumbs.
Cool for 10-15 minutes before removing from the pan.