Beat egg whites in stand mixer until stiff peaks form.
In a separate bowl, whisk yolks with ricotta, milk, and vanilla extract.
In a third bowl, whisk the flour with the sugar, baking powder, and salt.
Scrape the yolk mixture into the dry ingredients and stir just to combine, with some floury streaks remaining. Fold in beaten egg whites.
Lightly oil a large skillet and set over medium-low heat. Drop batter by scant 1/3 cupfuls, leaving ample space between to flip (I do a time). After a couple of minutes, when bubbles start to form at the surface and underside is golden brown, flip the pancakes. Contiuje cooking on other side until it's golden brown, too - about 2 minutes more. Transfer to wire rack and keep warm in a 200ºF oven. When ready to serve, dollop with yogurt and top with berries.