Before preparing the casserole, remove the chicken from the freezer and allow it to thaw slightly.
Preheat oven to 350°F. Place the frozen waffles on a baking sheet and bake them in the oven according to package directions. The toaster is also an option, but note every toaster differs!
While the waffles are baking, prepare the wet ingredient mixture. Add eggs, egg whites, milk, honey, salt, and ground cinnamon to a medium bowl. Whisk together thoroughly.
Once the waffles are finished, keep the oven on. Cut each waffle into six bite-sized pieces (half, then three even pieces). Set the pieces aside.
Pour the semi-frozen chicken onto a cutting board and slice each piece into ~1-inch pieces.
Generously coat a 9x13 baking dish with cooking spray. Combine the waffle pieces and chicken pieces in the dish. Arrange them so they’re evenly distributed in a single layer (some minor overlapping is okay).
Pour egg mixture over the chicken and waffles. Use a silicone brush to paint the maple syrup on the top of the casserole. Cover the dish with tinfoil.
Bake for 50 minutes on the middle oven rack. It’s fully cooked when the casserole/egg mixture has solidified and popcorn chicken and waffles are golden brown.
Top with extra maple syrup, light butter, and powdered sugar. Enjoy warm!