1 pkg. crushed Oreos (reserve 1 c. for topping)
2 pkg. (sm.) instant pistachio pudding
1 qt. vanilla ice cream, softened
1 (8 oz.) container Cool Whip
1 1/2 c. milk
1/3 c. butter

Melt butter and mix with cookies. Press into 9 x 13 inch pan. Mix pudding and milk. Add softened ice cream. Spread on crust. Spread Cool Whip on top. Sprinkle with remaining crumbs. Refrigerate overnight.