Whisk flour, sugar, salt, baking powder, baking soda in a bowl with a whisk. In a smaller bowl, whisk together the egg yolks, vanilla and buttermilk. Add the butter and whisk until well combined.
Add the buttermilk mixture to the flour mixture and mix until just combined. You want a fairly thick batter because that helps give height. If it is too thick, add a little of the milk until it is a workable consistency.
Add the egg whites and stir until they are mixed in. Let sit 5 minutes.
Heat a skillet over medium until hot. Reduce to medium low and spoon some batter onto the pan. If using chips or blueberries, add a layer and then spoon some more batter on top.
Cook until bubbles start to form and the edges of the pancakes are dry. Peek underneath and if golden, flip and allow to cook for 2 minutes or so until cooked through. Don't flip more than once or you will deflate them.
Serve hot with syrup or whipped cream.