Whisk together the flour, cornmeal, sugar, baking powder, salt, baking soda and nutmeg in a large bowl. Whisk together the egg yolks, buttermilk, melted butter and vanilla in a medium bowl. Whisk the buttermilk mixture into the flour mixture until just combined to make a thick batter.
In another bowl, whip the egg whites until they hold soft peaks. Use a rubber spatula to fold the whites into the batter just until no white streaks remain.
Heat a large nonstick skillet over medium heat and brush lightly with butter. Working in batches, drop about 1/4 cup batter per pancake into the skillet. Cook until bubbles form on the tops of the pancakes and the undersides are golden brown, about 2 minutes. Flip and continue to cook until the pancakes are cooked through, about 1 minute more. Transfer the cooked pancakes to the oven to keep warm and continue to make more pancakes, brushing the skillet with butter as needed, until all the batter has been used. Serve the pancakes with blackberries and maple syrup.
When measuring flour, we spoon it into a dry measuring cup and level off the excess. (Scooping directly from the bag compacts the flour, resulting in dry baked goods.)
Copyright 2016 Television Food Network, G.P. All rights reserved.