In a large bowl, whisk 1 cup ricotta cheese, 1 cup milk, 3 egg yolks, ¼ cup sugar, 3 tbsp lemon juice and 1 tbsp lemon zest until smooth and fully incorporated. Set aside.
Using a handheld electric mixer, a stand mixer fitted with the whisk attachment or a large bowl and a balloon whisk, beat the 3 egg whites until foamy. Add ⅛ teaspoon salt and continue whisking until you reach soft peaks.
Prep your pan by placing it on the stove on medium heat so it's ready as soon as you mix your wet and dry ingredients. In the meantime, go back to your ricotta cheese mixture and sift 1 ½ cups cake flour, 1 tbsp baking powder, and the rest of the salt over it. Stir until just combined (see note 1).
Then gently fold your egg white mixture into your batter a third at a time. What you're looking for is a light, fluffy mixture.
Put some oil or butter (or a combination) into your pan and pour the pancakes ⅓ cup at a time. Cook until golden brown at the bottom (2-3 minutes) then flip. Cook another 1-2 minutes (see note 2).
Serve warm topped with maple syrup and your favourite toppings like dried blueberries.
Do not over stir the batter. At this stage, you're not looking for a smooth and creamy mixture. Little lumps of flour is OK.
Every stove is different so time and watch your first couple of pancakes to see what the right cook time is for you.
These pancakes freeze really well. Just put them in a Ziploc bag (separated with parchment paper so they don't stick together) and freeze. Then just microwave each pancake for about a minute (no need to thaw) and you'll have good-as-new lemon ricotta pancakes!