Blueberry Refrigerator Pie

Heat oven to 350°F.

Reserve 1 Tbsp. butter. Melt remaining butter; mix with wafer crumbs. Press onto bottom and up side of 9-inch tart pan with removable bottom. Bake 10 min. or until golden brown.

Bring 1-1/2 cups blueberries, 1/2 cup sugar and 1 Tbsp. cold water to boil in saucepan, stirring constantly. Dissolve cornstarch in 3 Tbsp. of the remaining cold water; whisk into blueberry mixture. Simmer on low heat 2 min. or until thickened, stirring constantly. Remove from heat. Add reserved butter; stir until melted. Reserve 1/2 tsp. lemon zest and 1 tsp. juice. Stir remaining zest and juice into blueberry mixture; pour into crust.

Add boiling water to gelatin mix in medium bowl; stir 2 min. until completely dissolved. Add enough ice to remaining cold water to measure 1 cup. Add to gelatin; stir until slightly thickened. Remove any unmelted ice. Whisk 1 cup whipped topping into gelatin. Refrigerate 15 min. or until gelatin mixture is thick enough to mound. Stir in 1-1/2 cups of the remaining blueberries; spoon over blueberry layer in crust.

Refrigerate 4 hours or until firm. Top pie with remaining whipped topping. Toss remaining blueberries with reserved lemon zest, juice and remaining sugar; spoon over pie.