BOTTOM LAYER:

20 crushed Oreo cookies
1/3 c. melted butter

Press in 9x13 inch pan. Freeze for 15 minutes.

FILLING:

1/2 gallon softened ice cream

Place in freezer.

TOPPING:

2 sq. unsweetened baking chocolate
1 tbsp. butter
1/2 c. sugar
1 sm. can evaporated milk

Boil topping and cook until thick (2 to 3 minutes). Cool, let stand, and spread over top of ice cream.