LAYER 1:
1 lb. Oreo cookies, crushed
1/2 c. butter, melted

Mix together and press in 2 (9 x 13 inch pans, freeze.

LAYER 2:
1 gal. vanilla ice cream, slightly softened

Spoon on crust, freeze.

LAYER 3:
1 lg. can evaporated milk
1 c. sugar
2 sqs. semi-sweet chocolate
1/2 c. butter

Boil slowly 10 minutes, stirring occasionally. Cool completely. Spread over ice cream layer. Freeze.

LAYER 4:

Spread with large Cool Whip. Sprinkle with a few chopped walnuts and freeze.