Step 1

First, preheat your oven to 350°F (175°C) and grease a 9×13-inch baking pan.

Step 2

Then, melt butter in a saucepan, then add sugar, and stir well.
Beat eggs and vanilla in a separate bowl, then add to the saucepan and stir.

Step 3

After that, sift the flour, cocoa powder, and salt into the saucepan and stir until combined, then fold in chopped walnuts (optional), and pour the batter into the greased baking pan and spread evenly.

Step 4

Next, bake for about 25 to 30 minutes (until a toothpick comes out with a few moist crumbs).

Step 5

Then, while the brownies cool, prepare the frosting by melting butter, adding cocoa powder and milk, then whisking in powdered sugar and vanilla. Drizzle the luscious frosting over the cooled brownies, ensuring it covers the entire surface in a smooth, even layer.