Crush cookies. Melt 1/4 cup margarine or butter and combine with cookie crumbs;
spread in a 10-inch pie pan (could use 9- x13-inch pan) using back of spoon
around sides. Bake at 350°F. for 8 minutes. Cool completely.
Spread softened ice cream over crust. Freeze for at least an hour, even longer.
Fudge sauce: Melt 1/4 cup margarine in a saucepan; add sugar and cocoa, stirring
well. Add evaporate milk slowly, stirring until smooth. Cook over medium heat,
stirring constantly until thickened, about 4 to 5 minutes. Add vanilla; cool.
When cold, spread over ice cream layer. Return to freezer. Before serving,
spread with topping. If desired, sprinkle chopped nuts over topping.