If you're using milk and lemon juice instead of buttermilk, combine the two now and let it sit while preparing the rest of the batter.

Add the egg whites to a bowl and whip them up using a hand mixer until stiff peaks form. Set aside.

In another bowl, combine the flour, baking powder, baking soda, salt and sugar. Mix well before adding in the buttermilk or milk + lemon mixture, egg yolks, vanilla extract and melted butter. Use a whisk to combine the wet and dry ingredients well. Gently fold in the whipped egg whites - be careful not to overmix at this point, it could deflate the egg whites and leave you with a less fluffy batter.

Heat a skillet or griddle to medium heat, add a couple tablespoons of butter to the cooking surface and pour on the batter - I use about 1/4 to 1/3 cup per pancake. Let it cook until bubbles begin to form in the center of the pancake and the bottom looks golden brown. Flip and cook on the other side until cooked through. Continue with the rest of the batter adding more butter to the skillet if it dries. Enjoy with some melted butter and a drizzle of maple syrup!