Prepare the batter by separating egg whites and yolks. Combine yolks with milk, vanilla, and optional lemon zest. Sift in flour and baking powder until smooth.

Whip egg whites with vinegar or lemon juice until frothy, then gradually add sugar and continue until stiff peaks form.

Fold one-third of the whipped egg whites into the yolk mixture, then gently fold in the remaining whites until just combined.

Preheat a skillet on low heat, grease lightly, and spoon mounds of batter into the pan. Cook covered for 7-8 minutes, then flip and cook for another 5-6 minutes.

Serve stacked high with toppings like whipped cream, berries, powdered sugar, and maple syrup.