Prepare the crust: Combine the macadamia nuts, coconut, and brown sugar in a medium-size bowl. Beat the egg white until stiff, and gently fold it into the nut mixture.
Press the mixture evenly into an 8-inch pie plate, making sure the sides are thickish (the crust will shrink while baking). Bake until the crust is lightly browned, 7 minutes.
Remove the pie plate from the oven and let it cool on a rack. (The crust will tighten as it cools.)
Prepare the custard: Beat the egg yolks in a heavy medium-size saucepan. Add the cornstarch and sugar, and mix well. Then stir in the milk, salt, and butter.
Cook the egg mixture over medium heat, stirring constantly, until it is bubbling and thick, 5 to 7 minutes.
Remove the pan from the heat and stir in the vanilla. Transfer the mixture to a glass bowl, cover it with plastic wrap, and refrigerate for 2 to 4 hours.
Whip the cream with an electric mixer until it forms stiff peaks. Fold the whipped cream into the chilled custard.
Peel and slice 1 of the bananas, and arrange it evenly on the bottom of the reserved crust. Spoon the filling into the crust, cover with plastic wrap, and chill for another 2 hours.
When you are ready to serve the pie, sprinkle the chopped nuts evenly over the top. Then peel and slice the remaining banana, and arrange the slices in a circle on top of the pie, with a few slices placed decoratively in the center. Serve immediately.
Ingredients
Crust:
1 cup chopped unsalted macadamia or Delinut cashew nuts