In a 10-inch skillet stir together orange peel, orange juice, cornstarch, and ginger. Stir in undrained pineapple. Cook and stir until slightly thickened and bubbly.
In a small saucepan heat rum over low heat just until warm. Using a long match carefully, ignite rum and pour over pineapple mixture. Serve immediately over ice cream or frozen yogurt. Makes 6 servings.