Crustless Pistachio-Topped Sweet Potato Pie

Prepare topper: Preheat oven to 325 degrees F. Combine egg and water in a medium bowl. Beat with a wire whisk or fork until frothy. Add packed brown sugar and stir until combined. Stir in cereal flakes and pistachio nuts.

Lightly coat a 9x9x2-inch baking pan with nonstick cooking spray. Spread nut mixture in a thin layer in prepared pan. Bake for 10 to 15 minutes or until nuts appear dry, stirring once halfway through baking. Spread nut mixture on a piece of foil coated with nonstick cooking spray. Separate nut mixture into individual pieces or small clusters; cool completely. Set aside.

Preheat oven to 375 degrees F. Combine sweet potatoes, honey, brown sugar, orange peel, allspice and mace in a large bowl. Add egg. Beat lightly with a fork just until combined. Gradually stir in buttermilk. Pour into a 9-inch pie plate.

Bake for 35 to 40 minutes or until a knife inserted near the center comes out clean. Cool completely on a wire rack. Cover with foil and refrigerate within 2 hours. Sprinkle with Crunchy Pistachio Topper just before serving. If desired, top individual servings with whipped topping.