Combine the flour, baking powder, salt and sugar in a small bowl. Set aside.
Whisk together the ricotta cheese, eggs, milk, lemon zest and juice in a medium bowl. Gradually whisk in the flour mixture until well blended.
Heat a griddle to 350 degrees and coat with butter. Add 1/4 Cup batter to the griddle for each pancake and cook until bubbles appear on top. Flip and cook the other side until golden brown. Serve with raspberries and powder sugar if desired,