Cut cake into toast-size slices; spread 1 side with softened butter and sprinkle each with one teaspoon cinnamon and nutmeg.
Lightly brown the buttered sides in a large skillet while preparing other sides the same way.
After cooking both sides, remove toasted cake from skillet and place on a plate with about 1/3 cup melted vanilla ice cream, allowing cake to soak up the melted ice cream from the bottom.
Peel bananas and set aside.
In skillet over medium heat, melt 1 stick butter. Add orange juice and stir in brown sugar. Stir constantly over medium-low heat until mixture completely liquefies.
Add bananas to coat, cooking for about 2 minutes. Remove bananas to grill and continue to cook until tender.
Remove sauce from heat, add 2 tablespoons rum, and baste bananas with sauce while grilling. When bananas are cooked to your liking, return them to the skillet with the sauce. Slice as desired; diagonally works best.
Stir the remainder of the ice cream into a bowl of whipped cream and add 1 tablespoon rum.
Place a piece of cake on a dessert plate, cover with sliced grilled bananas, top with brown sugar sauce, and ladle vanilla rum sauce around the cake. Sprinkle with toasted coconut and serve.