Step 1In a large bowl, whisk together the egg yolks and ricotta cheese so that there are no large lumps of cheese, but make sure the mixture does not become too smooth (this will make the pancakes wet and grainy). Whisk in the sugar, salt and vanilla, then the milk.
Step 2In a separate bowl, whisk together the flour and baking powder. Fold this into the egg batter just until no lumps remain.
Step 3Separately, whip the egg whites to medium-stiff, shiny peaks, about 4 minutes. Gently fold these into the batter just until uniformly combined.
Step 4Ladle a generous one-fourth cup of batter onto a medium-hot, lightly greased griddle for each pancake. Place 10 to 12 blueberries on each pancake and cook, about 2 minutes per side, until the cakes are golden-brown and cooked through. Serve immediately with maple syrup on the side.