Add the sweetened condensed milk and Kool-Aid drink mix to a large mixing bowl. Beat with an electric mixer on low speed until fully combined.
Gently fold the thawed whipped topping into the mixture until no streaks remain and the filling is smooth and evenly colored.
Spoon the filling into the graham cracker crust and spread it into an even layer.
Cover and refrigerate for at least 2 hours, or until the pie is firm and fully chilled.
Slice and serve. Garnish with additional whipped topping if desired.
Christina's Notes
Any flavor of Kool-Aid drink mix works in this recipe, so it's easy to customize for holidays, parties, or your family's favorite flavor.
For a firmer texture, place the pie in the freezer. Let it sit at room temperature for about 30 minutes before slicing.
Sugar-free whipped topping can be substituted if preferred.
Store covered in the refrigerator for up to 4 days.
Freeze the pie tightly wrapped for up to 2 months. Thaw in the refrigerator before serving.