Dark Chocolate Brownies

Notes: These classic chocolate brownies can be stored in an airtight container for up to 2 days.
In a 2-to 3-quart skillet over low heat, stir the butter and chocolate frequently until they are melted and smooth. Remove from the heat and stir in the sugar, eggs, vanilla, flour and walnuts until smooth.Spread the dough evenly on a greased and floured 8-inch square baking dish.Bake in the oven at 350 ° until the edges are firm to the touch and a shade darker, 25 to 30 minutes.Swipe the knife between the edge of the mold and the brownie. If desired, spread with chocolate icing. Let cool in the pan on a wire rack for about 1 hour. Cut into 9 or 16 squares.Chocolate icing. In a 1-to 2-quart skillet over low heat, stir frequently 1/3 cup whipped cream and 1 cup (6 ounces) semisweet chocolate chips until melted and smooth. Add 1 teaspoon vanilla. Serve warm.Note: A nutritional analysis is provided for each small brownie.