In a medium bowl, whisk together flour, sugar, baking powder, and salt.
In a separate bowl, mix milk, egg yolks, vanilla extract, and melted butter.
Combine the dry and wet ingredients, stirring just until smooth.
In a clean bowl, beat egg whites until stiff peaks form. Fold into the batter gently.
Heat a non-stick skillet over low heat and pour the batter using a 1/3 cup measure. Cover with a lid and cook until bubbles form on the surface and the bottoms are golden brown.
Flip and cook for an additional 1-2 minutes until lightly browned.
Notes
Serve pancakes with fresh berries and a dollop of whipped cream for an extra treat.