Preheat oven to 350 degrees F. For crust, in a medium bowl combine 1 cup of the flaked coconut and the crushed graham crackers. Drizzle with melted butter; toss to combine. Press crumb mixture onto the bottom and up the sides of a 9-inch pie plate. Bake about 12 minutes or until golden. Cool on a wire rack.
For filling, in a medium saucepan stir together granulated sugar and cornstarch. Gradually stir in half-and-half. Cook and stir over medium-high heat until thickened and bubbly; reduce heat. Cook and stir for 2 minutes more. Remove from heat. Gradually stir about 1 cup of the hot mixture into egg yolks. Return egg yolk mixture to saucepan. Bring to a gentle boil, stirring constantly; reduce heat. Cook and stir for 2 minutes. Remove from heat. Stir in 2 tablespoons creme de cacao, 1 tablespoon of the butter, and the remaining 1 cup flaked coconut. Cover surface with plastic wrap; cool about 30 minutes.
In a small saucepan cook and stir white chocolate and the remaining 1 tablespoon butter over low heat until melted. Spread onto bottom of crust. Pour filling over white chocolate layer, spreading evenly. Cover and chill for 2 to 4 hours or until filling is set.
In a chilled medium mixing bowl beat whipping cream, powdered sugar, and, if desired, 1 1/2 teaspoons creme de cacao with an electric mixer until stiff peaks form (tips stand straight). Spread whipped cream over pie. Cover and chill for 30 minutes before serving. If desired, garnish with toasted coconut.