Start by making the pancake batter. Whisk together the eggs, flour, milk, sparkling water, salt, and sugar in a large bowl until you have a smooth batter.
Heat some oil in a non-stick pan over medium heat. Once hot, scoop ¼ cup portions of the batter into the pan and spread it out as thin as possible using the back of your spoon or ladle. Fry for about 2 minutes on each side or until golden brown. Set aside on a paper towel-lined plate once done.
To make the cottage cheese filling, beat the egg yolk, cottage cheese, or ricotta with an electric mixer until combined and creamy. Add in lemon zest, vanilla extract, and sugar and mix until combined.
To assemble the palacsinta Hungarian pancakes, spoon 1-2 tablespoons of the cottage cheese filling into the middle of each pancake and fold in half. Place them seam-side down on a large serving platter.
Serve with powdered sugar, apricot jam, or your favorite toppings!