Grab a large bowl and dump your crumbled leftover stuffing in. Crack in the eggs and stir everything together until it's evenly coated. If the mixture feels stiff or dry, add broth a tablespoon at a time. You want it moist enough to pack together but not runny.
Turn your waffle iron on and let it fully heat up before adding anything this is what gives you that crisp exterior instead of a pale, soggy waffle. Spray both plates generously with non-stick spray or brush on melted butter so nothing sticks.
Scoop about half the stuffing mixture onto the hot iron and spread it into an even, thin layer with a spoon or spatula. Unlike regular batter, this won't expand on its own, so take the extra few seconds to push it toward the edges yourself.
Close the waffle iron and let it cook for about 5 to 6 minutes. Resist the urge to peek early stuffing waffles need a bit longer than regular waffles because the egg has to cook all the way through, not just the outside.
Once it's deep golden brown and holds together when lifted, use a spatula to gently transfer it to a plate. Repeat the process with the remaining stuffing mixture, re-greasing the iron each time so the second waffle releases just as cleanly.
While the waffles are still hot, pour warm gravy over the top, add a spoonful of cranberry sauce, and layer on any leftover turkey you're using. Serve immediately so the crispy edges don't have time to soften.