In a large bowl, sift the flour, baking powder, baking soda, sugar and salt.
In a separate large bowl, mix together the buttermilk, egg yolks, melted butter, and vanilla extract until combined. Add the dry ingredients to the bowl and stir until just combined; batter will be slightly lumpy.
Place egg whites in a separate mixing bowl. Using an electric mixer, whisk until medium peaks form.
Gently fold half of the egg whites into the batter with a rubber spatula, then gently fold in the remaining whites.
Heat a griddle or large skillet over medium heat or 350° F. Add a little butter to the hot griddle or pan, once bubbling, add ½ cup pancake batter and let set. When bubbles begin to form, lift with a spatula and flip over. Cook until golden brown on both sides. Continue with remaining batter. Serve warm along with favorite toppings.