1. Working over a bowl, use a grater to zest the lemon, being careful not to remove any of the bitter white pith. Cut the zested lemon into wedges, and set them aside.
2. Add the raspberries to the bowl containing the lemon zest. Stir in 1/3 c sugar, gently crushing the raspberries with a wooden spoon. Set aside while making the pancake batter.
3. In a medium bowl, combine the flour, salt, 1 Tbsp sugar and baking powder. In another bowl, beat the ricotta cheese with milk and egg yolks. Add the flour mixture to the ricotta mixture, and stir until just combined. Let the batter sit for 10 minutes.
4. Beat the egg whites with a mixer until they hold soft peaks. Next gently fold the raspberries with their juices into the batter, then fold in the egg whites. (You want little clumps of whites in the batter. The important thing is not to overmix it.).
5. Heat a large nonstick skillet over moderately low heat. Melt 1/2 T butter at the center of the skillet, where you will spoon the batter.
6. Spoon the batter into the hot skillet, directly on the melted butter.
7. Cook each pancake until the bottom is golden brown and the bubbles on the surface begin to break, about 2 minutes. Using a spatula, flip the pancake quickly. Cook until golden brown, about 1 minute longer.
8. Serve finished pancake with maple syrup and lemon wedges.
9. Peaches and bananas work well in this recipe.