1 (15 oz.) pkg. Oreo cookies
1/3 c. melted butter
2 sm. pkg. instant pistachio pudding
1 1/2 c. milk
4 drops green food coloring
1 qt. vanilla ice cream, softened
1 (9 oz.) tub Cool Whip
Maraschino cherries (optional)

Crush cookies and mix with butter, press 2/3 of mixture on bottom of 13 x 9 pan. Prepare pudding, adding milk and food coloring. Stir in Cool Whip and ice cream. Mix thoroughly. Pour very carefully on crust. Top with remaining cookie crumbs. Put cherries on top if desired. Freeze. Remove from freezer 30 minutes before serving.