In a medium bowl, whisk together the ricotta, egg yolks, milk, and vanilla (or orange) extract until no lumps of ricotta are left.
With a wooden spoon or rubber spatula mix in the flour, baking powder, baking soda, sugar and salt until just combined.
In a small bowl, whisk the egg white until a little frothy. Fold the egg white into the batter until just combined.
Heat a non-stick or cast iron skillet over medium heat and melt the butter in the pan. With a paper towel, spread the butter around until the bottom of the pan is fully coated. (The butter will be mostly soaked up by the paper towel, but do not worry about this).
With a spoon or measuring cup, drop about 1/3 cup of batter into the center of the pan. Spread it into a round shape with a spoon. Let the pancake cook until the top starts to bubble a bit.
Flip the pancake with a spatula and cook on the other side for another minute or two, until there is no more raw batter visible on the sides of the pancake. Both sides should be deep golden brown.
Remove pancake to a plate and repeat with the rest of the batter. *There is no need to add butter after every pancake. You can add a bit now and then if you wish, spreading it around with the paper towel each time. *You will likely need to play with the heat periodically to keep the pan from getting too hot and burning the pancakes.