Spray pie dish with Pam and pack crushed graham crackers in it. When you take out pie slice, spoon loose crumbs on top.

FILLING:

1 (8 oz.) c. low-fat yogurt, vanilla
2/3 c. sugar
1 tsp. vanilla flavoring
1/3 c. cocoa
1 pkg. Dream Whip, whipped

Combine and spoon into graham cracker mixture.