In a large bowl, mix flour, sugar, baking soda, and salt.
Add the buttermilk, egg yolks, lemon juice, and lemon peel. Mix until evenly moistened.
Gently stir in ricotta cheese.
In a separate bowl, with a mixer on high speed, beat the egg whites until soft peaks form.
With a flexible spatula, gently fold the whites into the batter just until they are incorporated.
Next, add the blueberries. Gently stir in to combine.
Place a large, nonstick frying pan over medium heat; when hot, coat lightly with oil or butter and adjust heat to maintain temperature.
Drop batter onto the pan and cook until pancakes are browned on the bottom and edges begin to look dry, about 2 minutes.
Flip pancakes with a wide spatula and brown other sides, 1 1/2 to 2 minutes longer. Coat pan with more oil as necessary to cook remaining pancakes.
Flour: To keep the pancakes light and fluffy, it's important to properly measure the flour. To measure either weigh or stir or sift to break the flour up. Lightly spoon into the measuring cup and level. Avoid packing flour in.
Buttermilk: Regular or low-fat will work. If you don't have buttermilk, you can make an easy substitute with this recipe.
Lemon juice/zest: You should only need 1 lemon for the juice and the zest.
Ricotta cheese: You can use full-fat or part-skim. I don't recommend using fat-free in this recipe.
Blueberries: If you can't get fresh blueberries, you can use frozen blueberries. Use the blueberries frozen. Thawing them can give you mushy blueberries that bleed into the pancakes.