In a medium bowl, mix together flours, baking powder, sugar, and salt.
In a large bowl, mix together ricotta, milk, egg yolks, and vanilla. Add the dry ingredients to the ricotta and milk mixture, stirring gently until just combined.
In a small bowl, beat the egg whites with a handheld electric mixer or handheld whisk until stiff. Stir a small scoop of the egg whites into the pancake batter to lighten the batter, then fold in the remaining whites with a spatula.
Heat a griddle over medium-high heat. Melt a small bit of butter in the pan, just enough to coat the surface. Use a 1/3-cup measure to pour batter onto the hot griddle for each pancake. Cook the pancakes for about 3 or 4 minutes, until the undersides are golden and you see a few bubbles popping through the pancakes. Flip the pancakes and cook another 2 to 3 minutes, until golden. Repeat with the remaining pancakes.
Serve the pancakes immediately, with maple syrup, fruit jam, lemon curd, or powdered sugar.