Preheat oven to 350F. Lightly coat each cup of (2) 12-cup or (1) 24-cup miniature muffin tins with nonstick cooking spray. Set aside. For tartlet shells: In a medium bowl combine 3/4 cup granulated sugar, the egg whites and the coconut. Stir until the mixture is well blended and the coconut is moist. Put a scant tablespoon of coconut mixture into each prepared muffin cup. Press onto the bottom and up sides of cups. Set aside.

For filling: Combine almonds, 1/3 cup granulated sugar, butter, egg, vanilla, almond extract and orange peel in the bowl of a food processor. Process until almonds are finely ground and mixture is smooth. Fill each coconut shell with filling. If desired, garnish the top of each tartlet with additional slivered almonds. Bake until edges of crusts are golden and the filling is set, about 14-18 minutes. Remove from oven and set pan(s) on rack. Cool tarts in pan for 15 minutes. Run a knife around edges of tarts to loosen. Remove tarts; transfer to a rack and cool completely.