Chewy Fudgy Frosted Brownies

These are chewy fudgy and ultrarich brownies covered in a generous layer of creamy chocolate buttercream. The recipe starts with a combo of melted butter and quality chocolate which provides a smooth and velvety base for these dense fudgelike treats. Bake these in a 9inch square pan then cool for about 1 to 2 hours before frosting.
Ingredients
12 cup 8 Tbsp 113g unsalted butter
two 4ounce 226g semisweet chocolate bars coarsely chopped
34 cup 150g granulated sugar
14 cup 50g packed light or dark brown sugar

3 large eggs
1 teaspoon pure vanilla extract
23 cup 84g allpurpose flour spooned leveled
2 Tablespoons 10g unsweetened natural or dutchprocess cocoa powder I prefer dutchprocess
14 teaspoon salt
1 cup 180g semisweet chocolate chips
Chocolate Frosting
12 cup 8 Tbsp 113g unsalted butter softened to room temperature
1 and 12 cups 180g confectioners sugar
13 cup 27g unsweetened natural or dutchprocess cocoa powder I prefer dutchprocess
3 Tablespoons 45ml heavy cream or milk slightly warm see Note
12 teaspoon pure vanilla extract
pinch of salt to taste
Instructions
Make the brownies Cut the butter into smaller pieces so it melts down quicker. Place it in a heatproof bowl or in a medium saucepan. Add the chopped chocolate. Melt in the microwave in 20second increments stirring after each until melted or if youre using a saucepan melt it over low heat on the stove. Cool for just 5 minutes.
Meanwhile preheat the oven to 350F 177C. Line the bottom and sides of a 9inch square baking pan with parchment paper. Set aside.
Whisk the granulated and brown sugars into the cooled chocolatebutter mixture. Whisk in the eggs and then the vanilla. Whisk in the flour cocoa powder and salt until no pockets of dry ingredients remain. Once combined fold in the chocolate chips. The batter is semithick.
Pour and spread batter evenly into the prepared baking