01 -
Heat your oven to 350°F. Lightly grease a 9x13-inch baking pan and line with parchment paper so you can easily lift the brownies out later.
02 -
In a large bowl, stir together the melted butter and cocoa powder until smooth and glossy. Mix in the sugar until well combined, then beat in the eggs, vanilla, and salt until the batter looks silky.
03 -
Gently fold in the flour just until no dry streaks remain. Don't overmix or your brownies might turn out cakey instead of fudgy!
04 -
Pour the thick batter into your prepared pan, spreading it evenly to the corners. Bake for 18-20 minutes, or until a toothpick comes out with just a few moist crumbs clinging to it.
05 -
Allow the brownies to cool entirely in the pan before frosting. This patience will be rewarded with perfect texture!
06 -
Using a hand mixer, beat together the softened butter, milk, cocoa powder, powdered sugar, and vanilla until smooth and spreadable. If it seems too thick, add a tiny splash more milk.
07 -
Spread the chocolate frosting evenly over the cooled brownies, then let them set for about 30 minutes before cutting into squares.