Step 1: Prepare the crust. In a medium bowl, combine the vanilla wafer crumbs and melted butter. Mix well until crumbs are evenly moistened.
Step 2: Press the crust into a 12-cup muffin tin lined with paper liners. Use the bottom of a glass or your fingers to firmly press the mixture into an even layer, forming the bottom of each pie. Place in the refrigerator to chill while you prepare the filling.
Step 3: Make the cream cheese layer. In a large bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Add the powdered sugar and 1 teaspoon vanilla extract; beat until light and fluffy. Set aside.
Step 4: Prepare the vanilla pudding. In a separate bowl, whisk together the instant vanilla pudding mix and cold milk for about 2 minutes until it begins to thicken. Do not overmix.
Step 5: Gently fold the prepared vanilla pudding into the cream cheese mixture until just combined. Be careful not to overmix.
Step 6: Assemble the pies. Remove the muffin tin from the refrigerator. Place a few banana slices on top of each crust.
Step 7: Spoon or pipe the cream cheese pudding mixture over the banana slices, filling each liner to the top. Smooth the tops with a spoon or offset spatula.
Step 8: Chill the pies. Cover the muffin tin loosely with plastic wrap and refrigerate for at least 2 hours, or preferably 4 hours, until the pies are completely set.
Step 9: Prepare the whipped cream. In a clean, chilled bowl, beat the heavy cream, 2 tablespoons granulated sugar, and 1/2 teaspoon vanilla extract with an electric mixer on high speed until stiff peaks form.
Step 10: Garnish and serve. Once the mini pies are thoroughly chilled and set, remove them from the muffin tin. Top each pie with a generous dollop of whipped cream and an extra vanilla wafer, if desired. Serve immediately and enjoy!