Place egg yolks in a large bowl with the milk, vanilla, and melted butter. Whisk together.
Then add in the cornmeal, flour, sugar, baking powder, and salt. Stir until just combined, you do not want to over mix it.
In a medium bowl, add egg whites and whip until they form stiff peaks. Fold into the batter.
Add batter to a greased 9 x 13 inch baking dish and bake at 350 for 25-30 minutes until a toothpick inserted in the center comes out clean. Serves 15-18.
To make the maple butter: place butter butter in a bowl and whip until fluffy. Slowly add in the maple syrup and whip until combined. Serve with warm cornbread.