If making a homemade crust, combine graham cracker crumbs, melted butter, and sugar in a bowl. Press into the bottom and up the sides of a 9-inch pie pan until even. Chill in the fridge for 10 minutes to set.

In a medium bowl, pour the sweetened condensed milk. Add the thawed lemonade concentrate (or fresh lemon juice and simple syrup). Stir until glossy and smooth.

In a separate chilled bowl, whip your heavy cream to soft peaks, or simply stir the thawed whipped topping until silky.

Gently fold the whipped topping or whipped cream into the condensed milk and lemonade mixture. Use a spatula and a few patient folds so the filling stays fluffy.

Pour the filling into the prepared graham cracker crust, smoothing the top with the spatula.

Cover the pie loosely with plastic wrap and refrigerate for at least 4 hours, or overnight for a firmer set.

Before serving, add a sprinkle of lemon zest and a few thin lemon slices or mint leaves on top.