In a saucepan, combine the sugar, flour, and salt. Add milk in gradually while stirring gently. Cook over medium heat, stirring constantly, until the mixture is bubbly. Keep stirring and cook for about 2 more minutes, and then remove from the burner.
Add egg yolk mixture to the rest of the hot mixture. Keep stirring and cook for 2 more minutes. Remove the mixture from the stove then add butter and vanilla. Stir until the mixture reaches a smooth consistency.
Slice bananas into the cooled baked pastry shell. Top with pudding mixture.
Bake at 350º for 12 to 15 minutes. Chill for an hour. Top with whip cream and sprinkle with toasted coconut chips when ready to serve.