Preheat and Prepare the Waffle Iron: Preheat your waffle iron according to the manufacturer's instructions. If needed, lightly spray with cooking spray.
Mix the Dry Ingredients: In a large mixing bowl, whisk together the flour, brown sugar, baking powder, baking soda, cinnamon, nutmeg, and salt until well combined.
2 cups all-purpose flour, 2 tablespoons light brown sugar, 2 teaspoons baking powder, 1 teaspoon baking soda, ½ teaspoon ground cinnamon, ¼ teaspoon salt, ¼ teaspoon ground nutmeg
Combine Wet Ingredients: In a separate bowl, whisk together the eggnog, lightly beaten eggs, and butter until fully combined.
2 cups eggnog, 2 large eggs, 4 tablespoons unsalted butter
Combine Dry and Wet Mixtures: Pour the wet ingredients into the dry ingredients and gently whisk until the batter is smooth. Be careful not to overmix; a few small lumps are fine.
Cook the Waffles: Place the appropriate amount of batter onto the preheated waffle iron, close, and cook according to your waffle iron's specifications. (For example, our waffle iron uses about 1 cup of batter per waffle with a 4-minute cook time.)
Serve: Carefully remove each cooked waffle and transfer it to a plate. Repeat with the remaining batter. Serve hot with maple syrup, whipped cream, butter, powdered sugar, or a sprinkle of freshly grated nutmeg.