1 (19 ounce) can sweetened condensed milk
2 (16 ounce) cans frozen lemonade concentrate
2 (16 ounce) containers frozen whipped topping, thawed
2 cups heavy cream
1/3 cup confectioners' sugar for garnish
In a large bowl, combine sweetened condensed milk, lemonade concentrate, and frozen whipped topping. Beat at medium speed with electric mixer until just stiff peaks. Once cream has set, gradually add confectioners' sugar, one tablespoon at a time. Continue adding confectioners' sugar until all of the powdered sugar is incorporated.
Stir this mixture into heavy Filling Cup, then pour into a 9x13 inch glass. Chill until set before serving.