3/4 cups all-natural, whole-grain, crunchy, high-fiber, low-sugar cereal (I used Kashi 7 Whole Grain Nuggets)
2 tablespoons 100% pure maple syrup
1/4 teaspoon ground cinnamon
8 large egg whites
15-ounce can (1-¾ cups) solid pumpkin puree
3/4 cup agave nectar
2 tablespoons whole-wheat pastry flour
2-½ teaspoons vanilla extract
1-¼ teaspoons pumpkin pie spice
½ teaspoon baking powder
¼ teaspoon salt
32 teaspoons whipped topping, divided (optional)
Preheat the oven to 350 degrees. Spray an 11" x 7" glass or ceramic baking dish with spray.
Add the cereal to the bowl of a food processor fitted with a chopping blade. Process it for 15-20 seconds, or until the cereal is crushed. Transfer it to a small mixing bowl and add the maple syrup and cinnamon. Mix them until well combined (the mixture should be slightly sticky). Spoon the mixture into the prepared baking dish. Using a small piece of parchment paper, gently press down on the cereal mixture, spreading it evenly across the bottom of the baking dish. Bake the crust for 7-9 minutes, or until it is slightly browned. Set aside.
Meanwhile, add the egg whites to a large mixing bowl. Using a sturdy whisk, lightly beat them until they bubble very slightly. Still using the whisk, stir in the pumpkin, agave, and flour until well combined. Stir in the vanilla, pumpkin pie spice, baking powder, and salt and continue mixing until well combined. Pour the filling over the baked crust. Using a rubber spatula, spread it into an even layer.
Bake for 40-45 minutes, or until a toothpick inserted in the center comes out dry (a few crumbs are okay). Transfer the dish to a wire cooking rack, allowing it to cool to room temperature. Carefully cut 32 pumpkin "bites" (3 cuts along the width of the pan, 7 cuts along the length, creating 4x8 bites).
Just before serving, top each bite with 1 teaspoon whipped topping, if desired. Serve immediately or store in an airtight container in the refrigerator for up to 5 days.