In a skillet, saute coconut in butter until golden. Press all but 2 tablespoons into the bottom and up the sides of a greased 9" pie plate. Bake at 350 for 7 minutes.
In a saucepan, combine the sugar, flour, cornstarch and salt. Gradually add cream and bring to a boil. Cook and stir constantly for 2 minutes. Add a small amount to egg yolks. Return all to pan; cook for 2 minutes. Remove from heat; add vanilla. Cool to room temperature.
Place sliced bananas in the crust. Cover with cream mixture. Chill until set, about 2 hours. Sprinkle with reserved coconut. If desired, garnish with whipped cream and bananas.