1/4 cup butter, softened
1/2 cup sugar
1 egg
1/2 teaspoon vanilla extract
1/4 cup all-purpose flour
3 tablespoons baking cocoa
1/4 cup chopped walnuts
FROSTING:
1/2 cup confectioners' sugar
1 tablespoon baking cocoa
2 1/2 teaspoons milk

In a small mixing bowl, cream butter and sugar. Beat in egg and vanilla. Combine the flour and cocoa; gradually add to creamed mixture. Stir in walnuts.
Coat a 6-in. round springform pan with nonstick cooking spray and dust with sugar; add the batter. Place pan on a baking sheet. Bake at 350 degrees F for 20-25 minutes or until a toothpick inserted near the center comes out clean. Cool on a wire rack.
Remove sides of pan. In a small bowl, combine frosting ingredients. Spread over pie.