Preheat your oven to 350°F (175°C).
Prepare the pie crust by mixing flour, butter, and sugar, then press it into a pie dish.
Bake the crust for 10-12 minutes until golden brown.
In a saucepan, whisk together sugar, cornstarch, and salt.
Gradually add milk while stirring to avoid lumps, and bring to a boil.
Once boiling, reduce heat and cook for another 2 minutes until thickened.
Remove from heat and stir in vanilla extract and butter.
Slice bananas and layer them in the baked crust.
Pour the cream mixture over the bananas, smoothing the top.
Chill in the refrigerator for at least 4 hours before serving.