Preheat oven to 400 degrees F (200 degrees C). Spread chicken nuggets out on a baking sheet.
Bake nuggets in the preheated oven until hot and crispy, 11 to 13 minutes.
Preheat a waffle iron according to manufacturer's instructions and lightly coat with cooking spray.
Whisk flour, cornmeal, sugar, baking powder, salt, baking soda, black pepper, and cayenne pepper together in a bowl. Whisk buttermilk, oil, and eggs together in another bowl. Pour buttermilk mixture into flour mixture and stir until batter is just-combined.
Place 1 chicken nugget in the center of each waffle section on the waffle iron. Cover each nugget with about 1 tablespoon of batter, close the waffle iron, and cook until golden and crisp, about 4 minutes. Repeat with remaining nuggets and batter.