Preheat your oven to 350°F (175°C). Grease and line an 8x8-inch baking pan with parchment paper.

In a large bowl, combine the granulated sugar and melted butter. Stir until well mixed.

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

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

Gradually add the dry ingredient mixture to the wet ingredients, stirring just until combined. Be careful not to overmix.

Fold in the brewed coffee until just incorporated. Pour the brownie batter into the prepared baking pan, spreading it evenly.

Bake in the preheated oven for 20-25 minutes. A toothpick inserted into the center should come out with a few moist crumbs but not wet batter.

Once done baking, remove from the oven and allow the brownies to cool completely in the pan before frosting.

For the frosting, beat the softened butter in a bowl until creamy.

Gradually add the powdered sugar and beat until fluffy.

Mix in the brewed coffee and vanilla extract, beating until smooth. Spread the frosting over the cooled brownies and sprinkle with a pinch of cocoa powder if desired.