In contrast to some brownie recipes that incorporate melted chocolate into the batter, this particular recipe relies on cocoa powder for its chocolatey kick. Cocoa powder contributes to a chewier texture because the only fat source here is butter, not additional chocolate. Feel free to make this recipe your own! If you're craving extra chocolate goodness, we suggest mixing 2 to 3 tablespoons of chocolate chips into the batter before baking, or simply sprinkling them on top.