1 stick butter
2 c. crushed Ritz crackers
2 1/2 c. (scant) milk
2 c. vanilla ice cream
2 pkg. pistachio pudding mix
1 sm. tub Cool Whip

Mix crackers and butter. Place in bottom of 9 x 13 inch pan. Mix separately milk and vanilla ice cream. Add pudding mix and pour over crackers in the pan. Refrigerate overnight or until set. Spread Cool Whip over the top. Decorate with chocolate slivers.