Stir together the egg yolks, ricotta, buttermilk, and vanilla extract in a large bowl. Make sure to break apart any large lumps of ricotta.
In a separate bowl, stir together the flour, baking powder, salt, and sugar.
Add the flour mixture to the wet mixture and mix it together until just combined.
In a medium sized bowl, add your egg whites. Whisk them with a hand beater (or by hand) for about 1 minute until nice and foamy, and starting to stiffen. Stir once with a rubber spatula to get the egg whites at the bottom and beat together again.
Pour the egg whites into the batter and fold them together.
Heat a nonstick skillet or griddle over medium heat.
Spread top of skillet or griddle with butter.
Pour 1/3 of a cup of batter onto the skillet. Gently spread it out a little with the measuring cup.
Cook for about 2 minutes, or as long or as little as it takes till the top start to bubble and the bottom is golden underneath.
Flip and cook the bottom side for about 1 minute until done.
Remove from skillet and repeat with additional batter. Spreading more butter as needed.
Serve pancakes hot topped with fresh fruit, syrup, whipped cream, etc.