Blueberry Fluff Pie

20 large marshmallows
1/4 cup milk
4 cups fresh blueberries, divided
1 (8 ounce) carton frozen whipped topping, thawed
1 (9-inch) pastry shell, baked

In heavy saucepan, combine marshmallows and milk. Cook and stir over medium-low heat until marshmallows melted and mixture smooth. Cool 8-10 minutes, stirring several times.

Stir in 3 1/2 cups blueberries. Set aside 1/2 cup whipped topping; fold remaining topping into blueberry mixture. Pour into crust. Refrigerate at least 2 hours.

Garnish with remaining blueberries and reserved topping.