Preheat your oven to 350°F (175°C). Prepare an 8-inch baking dish by coating it with non-stick spray or lining it with parchment paper, then give it a light spray.

In a microwave-safe bowl, melt the butter. Once melted, transfer it into a large mixing bowl.

Add sugar, eggs, and vanilla extract to the bowl, stirring until everything is thoroughly blended.

Gradually mix in the flour, cocoa powder, salt, and baking powder until the batter is smooth.

Spread the batter evenly into the prepared baking dish and pop it in the oven.

Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.

Let the brownies cool completely before moving on to the frosting.

For the frosting, dissolve the instant coffee granules in the heavy whipping cream and set it aside.

In another bowl, beat the unsalted butter until light and fluffy, then gradually mix in the powdered sugar.

Slowly pour in 2 tablespoons of the coffee-infused cream, mixing until smooth. If needed, add more cream, 1 tablespoon at a time, until you reach your desired consistency.

Spread the frosting generously over the cooled brownies, slice, and serve!