Lightly spoon flour into a dry measuring cup, and level with a knife. Combine flour, sugar, baking powder, baking soda, and salt in a large bowl. Combine ricotta cheese and next 4 ingredients (cheese through yolks), and add to the flour mixture, stirring until smooth. Beat egg whites at high speed of a mixer until stiff peaks form. Gently fold one-fourth of egg whites into cheese mixture; gently fold in remaining egg whites.
Spoon about 1/4 cup batter onto a hot nonstick griddle or large nonstick skillet. Turn pancakes when tops are covered with bubbles and edges look cooked.