2 (8 oz.) containers fruit flavored yogurt
1 (9 oz.) container Cool Whip
1 graham cracker pie shell

Fold yogurt into whipped topping, blending well. Spoon into crust. Freeze until firm, 4 hours or overnight. Move to refrigerator at least 30 minutes (or longer for a soft texture) before cutting. Garnish, if desired, with Cool Whip or fresh fruit. Store any leftover pie in the refrigerator.