For The Brownies
1 1/4 cups all purpose flour
1 teaspoon salt
2 tablespoons dark unsweetened cocoa powder
11 ounces dark chocolate, coarsely chopped
1 cup (2 sticks) unsalted butter, cut into 1-inch pieces
1 1/2 cups granulated sugar
1/2 cup firmly packed light brown sugar
5 large eggs, at room temperature
2 teaspoons pure vanilla extract

For The Mint Filling
2 cups confectioner’s sugar
1/2 cup (1 stick) unsalted butter
2 to 3 tablespoons heavy cream
1 1/2 teaspoons mint extract
2 drops green food coloring (optional)

For The Ganache Glaze
6 ounces chocolate chips or chopped chocolate
3 ounces butter