Preheat a round electric waffle iron on low or a stovetop waffle iron over medium-low heat; spray with cooking spray.
Whisk the flour, cornmeal, sugar, salt and baking soda together in a large bowl; set aside.
In the bowl of a stand mixer, beat the 2 egg whites until soft peaks form. In a large bowl, whisk the 2 egg yolks, buttermilk and vanilla until combined, then slowly drizzle in the 4 tablespoons melted butter while whisking. Using a rubber spatula, gently fold the egg whites into the yolk mixture until just combined. Gently stir in the club soda. Pour the mixture over the dry ingredients and fold until just combined (there should still be plenty of lumps). Add the stuffing and mix just to combine.
Spoon about 1 cup batter onto the waffle iron, gently spreading until the batter almost touches the edges. Close the iron and cook until golden brown, 4 to 5 minutes. Transfer the waffle to a plate, or keep warm on a rack in a 200-degree F oven. Repeat with the remaining batter.
Melt the 2 tablespoons butter in a large nonstick skillet over medium heat. Fry the 6 eggs, sunny-side up, until the whites are set but the yolk is still runny.
To serve, lay 1 or 2 slices of turkey atop a waffle and top with a fried egg. Drizzle with maple syrup.