Trilevel Brownies

• 1/2
  cup all-purpose flour
• 1
  cup quick-cooking rolled oats
• 1/2
  cup packed brown sugar
• 1/4
  teaspoon baking soda
• 1/2
  cup butter, melted
• 1
  egg
• 3/4
  cup granulated sugar
• 2/3
  cup all-purpose flour
• 1/4
  cup milk
• 1/4
  cup butter, melted
• 1
  ounce unsweetened chocolate, melted and cooled
• 1
  teaspoon vanilla
• 1/4
  teaspoon baking powder
• 1/2
  cup chopped walnuts
• 1
  ounce unsweetened chocolate
• 2
  tablespoons butter
• 1 1/2
  cups sifted powdered sugar
• 1/2
  teaspoon vanilla
• Walnut halves (optional)

Directions

1. For bottom layer, stir together oats, the 1/2 cup flour, the brown sugar, and baking soda. Stir in the 1/2 cup melted butter. Pat mixture into the bottom of an ungreased 11x7x1-1/2-inch baking pan. Bake in a 350 degree F. oven for 10 minutes.

2. Meanwhile, for middle layer, stir together egg, granulated sugar, the 2/3 cup flour, the milk, the 1/4 cup melted butter, 1 ounce melted chocolate, the 1 teaspoon vanilla, and the baking powder until smooth. Fold in chopped walnuts. Spread batter over baked layer in pan. Bake about 25 minutes more or until a wooden toothpick inserted in center comes out clean. Set on a wire rack while preparing top layer.

3. For top layer, in a medium saucepan heat and stir 1 ounce chocolate and the 2 tablespoons butter until melted. Stir in the powdered sugar and the 1/2 teaspoon vanilla. Stir in enough hot water (1 to 2 tablespoons) to make a mixture that is almost pourable. Spread over brownies. If desired, garnish with walnut