Preheat the oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper and lightly grease it.

In a large microwave-safe bowl or saucepan, melt the butter. Stir in the granulated sugar and brown sugar until well combined.

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

In a separate bowl, whisk together the flour, cocoa powder, salt, and baking powder.

Add the dry ingredients to the wet ingredients and mix just until combined. Fold in the chocolate chips.

Spread the batter evenly into the prepared pan.

Bake for 28 to 32 minutes, or until the edges are set and a toothpick inserted in the center comes out with a few moist crumbs. Do not overbake for maximum fudginess.

Cool the brownies completely in the pan before decorating.

Once cooled, spread a thin, even layer of chocolate frosting over the top.

Use white decorating icing or melted white chocolate to pipe football laces on each brownie, then cut into football-shaped or standard square portions. Garnish with optional toppers or sprinkles if desired.