Mix the graham cracker crumbs, melted butter, and sugar together in a bowl until fully combined. Stir until the texture resembles wet sand. Press the mixture firmly into the bottom of muffin tin cups or dessert jars.
Refrigerate the crusts for about 10–15 minutes to allow them to set.
In a separate bowl, whisk the cold milk and instant pudding mix until smooth and well blended. Allow the pudding to sit for about 5 minutes to thicken.
Place a layer of thinly sliced bananas on top of the prepared crust. Spoon the pudding mixture on top and add a dollop of whipped topping.
Optional: sprinkle with crushed vanilla wafers or place one whole wafer on top. Refrigerate the assembled pies for a minimum of 1 hour to let them set before serving.
