Grease waffle iron with a small amount of melted butter, and heat. In a large bowl, sift together the flour, sugar, baking soda, baking powder, cinnamon, and salt.
In a separate bowl, whisk together egg yolks, buttermilk, melted butter, and vanilla. Pour into dry mixture, and combine.
In a medium bowl, beat egg whites until stiff but not dry. Fold whites into batter.
Ladle about 1/3 cup batter onto each section of the waffle grid; spread batter almost to the edges. Close lid, and bake 3 to 5 minutes, until no steam emerges from waffle iron.
Transfer cooked waffles to a baking sheet; place in an oven set to low heat, about 200 degrees, while using remaining batter.
On the TV show, Martha used 1 vanilla bean, split and scraped, instead of vanilla extract and baked waffles 5 to 7 minutes.