Separate the egg whites from the yolks, placing the whites in a clean, grease-free bowl.

In a separate bowl, whisk together the egg yolks, milk, vanilla extract, and optional lemon zest until smooth. Sift in the flour and baking powder, gently stir until consistent.

Add white vinegar to the egg whites and whip until frothy. Gradually add sugar and whip until stiff peaks form.

Gently fold one-third of the meringue into the yolk mixture. Repeat with the remaining meringue in two more additions, folding until just combined.

Preheat a nonstick pan over low heat and grease it lightly. Aim for a temperature between 285°F and 320°F.

Place dollops of the batter onto the pan to create rounds. Cover and cook for 7-8 minutes, then flip and cook for an additional 5-6 minutes.

Stack the pancakes on a plate and serve immediately with your choice of toppings.