A pound of peaches can be used instead of nectarines.
Combine the first 6 ingredients in a large bowl; cover and marinate the fruit mixture 30 minutes in refrigerator, stirring occasionally.
Place a large nonstick griddle or nonstick skillet coated with cooking spray over medium-high heat until hot. Arrange the angel food cake slices in a single layer on pan, and cook for 2 minutes on each side or until the cake slices are toasted.
Place 1 cake slice on each of 8 plates, and top each slice with 3/4 cup marinated fruit mixture. Drizzle each cake slice with 1/4 cup Orange Custard Sauce.