This decadent Chocolate Brownie Frosting is the best! Cocoa powder, sugar, butter, and peanut butter create a thick frosting that hardens on top of rich brownies as soon as it sets. It’s the perfect pairing for any chocolate brownie, homemade or box!
In a medium-sized bowl add melted butter and cocoa powder and use a electric hand mixer to mix until well combined. Add in powdered sugar, peanut butter, milk and vanilla and continue to mix until creamy.
Spread over warm brownies and allow to cool (this will set the frosting) before cutting the brownies.