Whisk the egg yolks, milk, and vanilla in a bowl.
Add flour, baking powder, and salt to the egg yolk mixture. Mix well and set aside.
With your electric hand mixer or stand mixer with whisk attachment, beat egg whites until frothy. Add sugar and continue to beat egg whites to stiff peaks.
Set your skillet on low heat and add a small pat of butter, letting it melt while you prepare the batter.
While skillet is warming up, mix your batter by combining about ⅓ of the stiff egg whites to your egg yolk mixture. Use a rubber spatula to fold it in. When batter is homogenous, add the rest of the egg whites and gently fold to combine, taking care not to overmix.
By this time, your skillet should be warm enough to begin cooking your pancakes. Use your cookie scoop to place 4-5 scoops spaced out in your skillet. Add a second round of scoops on top of your original 4 or 5. Carefully pour 1 tablespoon of water into your skillet, avoiding the pancake batter. Quickly cover your skillet with a lid and set a timer for two minutes.
After two minutes, remove lid and add an additional scoop of batter onto each pancake. Replace lid and continue cooking on low-medium heat for another 5-6 minutes.
Uncover your skillet. By this time, the bottom of your pancakes should be a golden brown. If they are not, increase your heat and cook for another minute, watching your pancakes carefully so they don't burn. When they are golden brown on the bottom, carefully flip over your pancakes. Sprinkle another tablespoon of water into the skillet and cover.