double fudge frosted brownies

Ingredients

• 1/2 cup (1 stick) unsalted butter, room temp
• 1/2 cup lightly packed light brown sugar
• 6 ounces semisweet chocolate, chopped
• 2 ounces unsweetened chocolate, chopped
• 1/4 cup granulated sugar
• 3 large eggs
• 1 1/2 teaspoons vanilla extract
• 1/2 cup all purpose flour
• 1/3 teaspoon kosher salt
• chocolate chips and or toasted nuts (to taste, optional)
• 3 tablespoons unsalted butter, but into tablespoons
• 2 ounces unsweetened chocolate
• 1 ounce milk chocolate
• 1 1/2 cups confectioners’ sugar
• 1/4 teaspoon kosher salt
• 1/4 cup heavy cream
• 1 teaspoon vanilla extract