Spray a 13x9-inch cake pan with cooking spray. Line with parchment paper, leaving an overhang over the sides. This will help you lift the bars out of the pan later.
In a food processor, blend together flour, butter, powdered sugar, and salt until the mixture resembles coarse sand. This will not look like dough – that’s ok! Press firmly into the bottom of the prepared pan. Bake until the edges are golden, about 20 minutes. Let cool completely.
In a large bowl, whisk together the sweetened condensed milk and whole milk to combine. Whisk in the pudding mix. Whisk for two minutes.
Spread half of the pudding mixture over the cooled crust. Top evenly with the sliced bananas. Spread the remaining pudding over the top. Cover and refrigerate for at least 2-3 hours.
Spread the thawed whipped topping over the top of the filling.
Use the parchment paper to lift the bars out of the pan. Cut into slices and serve.
If desired, garnish with additional slices of banana or vanilla wafer crumbs just before serving.
Notes
Store covered in the refrigerator for up to 3 days.For a thinner layer of whipped topping, just 1 (8-ounce) container instead of 2.For cleaner slices, place the bars into the freezer for about 20 minutes before removing from the pan and slicing.Helpful resources:
Make sure you know how to measure flour correctly so your crust always turns out perfect.