Cream eggs, sugar, butter and vanilla with mixer. Add in flour and milk and continue mixing. Stir in mashed banana with spoon. Spray a 10 inch pie plate with cooking spray and pour in ingredients. Bake in a preheated 350 degree oven 60 to 65 minutes until brown on top.
This pie will rise up during baking and then fall after it begins to cool. I always put a baking sheet under this pie to catch any drips when it rises up in the oven. The pie will slice better if you let it cool in the refrigerator before slicing.