HEAT oven to 325ºF.
MIX graham crumbs, sugar and butter; press onto bottom and up side of 9-inch pie plate. Bake 10 min. Meanwhile, mash 1 cup strawberries. Slice remaining berries; refrigerate until ready to use.
ADD boiling water to gelatin mixes in medium bowl; stir 2 min. until completely dissolved. Stir in mashed berries until blended. Refrigerate 45 min. or until slightly thickened.
WHISK yogurt into gelatin mixture until blended. Refrigerate 20 min. or until thick enough to mound. Pour into crust.
REFRIGERATE 4 hours or until firm. Spread COOL WHIP over pie; top with sliced berries.