Cherry Crumb Dessert

1/2 cup butter or margarine, chilled
1 (18 1/2 ounce) box yellow cake mix
1 (21 ounce) can cherry or blueberry pie filling
1/2 cup chopped walnuts
Whipped cream or ice cream (optional)

In a mixing bowl, cut butter into cake mix as for pastry dough. Set aside 1 cup. Pat remaining crumbs onto the bottom and 1/2 inch up the sides of a greased 13 x 9-inch baking pan. Spread pie filling over crust. Combine the walnuts with reserved crumbs; sprinkle over top. Bake at 350 degrees F for 30 to 35 minutes.

Serve warm, with whipped cream or ice cream, if desired.

Yields 12 to 16 servings.