Separate the eggs and beat the egg whites until they hold stiff peaks.
In a separate bowl, stir together all remaining ingredients: egg yolks, flour, ricotta cheese, melted butter, salt, lemon zest and vanilla. Mix well.
Fold in egg whites with a spatula. Mix in gently; there will be small pieces of egg white showing.
Heat a skillet over medium heat. Grease lightly (ghee, butter.) Use a large spoon to drop mixture onto skillet.
Serve with raspberry sauce, fresh fruit and or and maple syrup.