Cooking : Black 'N' White Brownies

Ingredients
3/4 cup all-purpose flour
1/2 cup sugar
1/4 teaspoon baking powder
1/4 teaspoon salt
1 cup quick-cooking oats
1 cup flaked coconut
2/3 cup butter, melted
2 tablespoons milk
CHOCOLATE LAYER:
1/3 cup butter
1 (1 ounce) square unsweetened chocolate
1 cup packed brown sugar
2 tablespoons milk
1 teaspoon vanilla extract
3/4 cup all-purpose flour
1/2 teaspoon baking powder
1/4 teaspoon salt
1/2 cup chopped walnuts
4 ounces cream cheese, softened
1/4 cup butter, softened
1 1/2 teaspoons vanilla extract
2 1/4 cups confectioners' sugar
1/4 cup chopped walnuts

Directions
In a bowl, combine the first four ingredients. Stir in oats and coconut. Add butter and milk; mix well. Press into a greased 13-in. x 9-in. x 2-in. baking pan. Bake at 350 degrees F for 10-12 minutes. Remove from the oven. Reduce heat to 325 degrees F.
In a saucepan, melt the butter and chocolate; cool slightly. In a mixing bowl, combine the eggs, brown sugar, milk and vanilla; mix well. Add chocolate mixture; mix well. Combine the flour, baking powder and salt; add to chocolate mixture and mix well. Stir in walnuts. Spread evenly over crust. Bake at 325 degrees F for 25-30 minutes or until a toothpick comes out with moist crumbs (do not overbake). Cool on a wire rack.
In a mixing bowl, combine the first four frosting ingredients until smooth and creamy. Spread over bars. Sprinkle with walnuts. Store in the refrigerator.