Combine pudding mix and milk. Fold in Cool Whip. Line 9 x 13 inch pan with crackers. Spread half of pudding mixture over crackers. Repeat cracker, pudding, cracker layers. Combine sugar, cocoa and Pet milk. Boil 1 minute, stirring constantly. Add vanilla and margarine. Pour into pan as a topping. Refrigerate 1 hour. Freezes well.
Cajun Country -- New Iberia, Louisiana