Combine 45 Ritz crackers and 1 stick butter, melted and pat in 13"x9" cake pan. Beat 2 packages instant pistachio pudding with 1 1/2 cups milk. Add 1 quart softened vanilla ice cream. Chill. Top with 1 medium size carton Cool Whip (or 2 cups prepared Dream Whip), 4 cups (frozen) $.15 Heath bars sprinkled over top. Freeze until ready to serve.