For crust, stir together 1 cup of the coconut, graham crackers, and melted butter. Press onto bottom and up sides of a 9-inch pie plate. Bake in a 350 degree F oven for 10 minutes. Cool on a wire rack.
For filling, in a large heavy saucepan heat milk and remaining coconut just to simmering, stirring occasionally.
Meanwhile, in a mixing bowl combine egg yolks, granulated sugar, and flour. Beat with an electric mixer on medium-high speed until combined. Gradually stir 1 cup of the hot milk mixture into the egg yolk mixture. Return all of the yolk mixture to the saucepan. Cook and stir until mixture comes to boiling. Cook and stir for 2 minutes more. Remove saucepan from heat. Stir in 1 tablespoon of the butter and the 2 tablespoons creme de cacao. Cover surface with clear plastic wrap; cool.
Meanwhile, in a small saucepan melt white baking bar with remaining 1 tablespoon butter over low heat, stirring constantly. Spread onto bottom and sides of cooled crust. Cool until white baking bar is firm. Pour filling into crust. Cover and chill pie for 2 to 4 hours.
Thirty minutes before serving, in a chilled mixing bowl beat whipping cream, powdered sugar, and, if desired, the 1 tablespoon creme de cacao until stiff peaks form (tips stand straight). Swirl whipped cream over pie. Cover and chill for 30 minutes. If desired, garnish with coconut or white baking bar curls. Makes 8 servings.