Make the soufflé pancake batter: Separate the egg whites and egg yolks into separate mixing bowls. Make sure to not break the yolk! Add the milk, vanilla, and lemon zest to the yolks and whisk briefly until combined. Sift in the flour and baking powder and whisk until smooth. Set aside.
Beat the egg whites with vinegar or lemon juice on medium speed until frothy. Gradually add the sugar, then increase the speed to medium-high and beat until stiff peaks form.
Gently fold ⅓ of the meringue into the yolk mixture until evenly combined, then fold in the rest. Be careful not to overmix.
Cook the pancakes: Heat a nonstick pan over low heat with a little oil. Wipe excess oil. Portion the batter into 2-3 mounds in the pan, cover with a lid, and cook for 7-8 minutes. Flip, then cook for another 5-6 minutes.
Serve immediately with optional toppings.