Mix the ricotta cheese, egg yolks, sugar, orange zest, orange juice, and buttermilk in a large bowl.
In a separate bowl, mix the flour, baking powder and salt.
Combine the wet and dry ingredients, being careful not to over-mix; it is OK if there are a few lumps in the mixture.
Meanwhile, beat the egg whites in a bowl until soft peaks just start to form.
Gently fold the egg whites into the pancake batter, being careful not to deflate the egg whites.
Heat a nonstick skillet over medium-low heat and add ½ tablespoon of butter.
Pour about ⅛ cup of the pancake batter in the pan and cook until they start to bubble (about 2 minutes).
Flip and cook the other side for about 1-2 minutes. Pancakes should be golden brown on both sides, and cooked through. Remove and place on a plate (keep warm in a 200F degree oven).
Repeat until all batter is gone, adding ½ tablespoon of butter between each batch.
Notes
Don't over mix the batter - your pancakes will become tough and gummy. It's ok for the batter to have a few lumps in it.
Add more orange zest for a stronger orange flavor.
Use a nonstick skillet to keep the pancakes from sticking - add more butter if necessary.
Keep them warm in a 200F degree oven while you make the remaining pancakes.
You can make the batter (less the egg whites) ahead of time and store covered in the fridge overnight. When you’re ready to make the pancakes, whip the egg whites per the recipe instructions and fold into the batter.
To freeze pancakes, place them on a baking sheet directly in the freezer until frozen about 2-3 hours. Wrap them individually in plastic wrap or waxed paper and store them in a freezer bag for up to one month. Pancakes can be reheated in the microwave for about 30 seconds (or until warmed through) or reheated in a 375 degree oven for 10-15 minutes (until warmed through).