In a blender, add 2 scoops (100 grams) of chocolate ice cream, 1 cup (250 ml) of cold milk, and 1 tablespoon (15 grams) of chocolate syrup. Blend until smooth and creamy.
Break 1 medium-sized (50 grams) chocolate brownie into small pieces and add it to the blender. Pulse the blender a few times to mix the brownie pieces into the milkshake, leaving some chunks for texture.
Pour the brownie milkshake into a tall glass and garnish with whipped cream, chocolate syrup, and a few small brownie pieces on top.