Add the sugar to a large bowl, then finely grate the zest of the lemon directly over the sugar. Using a rubber spatula or your fingers, gently rub the zest into the sugar. Add the vanilla and whisk to evenly moisten. Add the eggs and whisk until foamy on top, then add the ricotta, buttermilk and butter, and whisk until well blended. Add the flour mixture and gently stir until no traces of flour remain.

Heat a griddle or large nonstick pan or well-seasoned cast-iron skillet over medium-low. Generously butter the griddle, then drop a scant ¼ cup batter onto it. Repeat, spacing the rounds at least an inch apart. Cook until the bottoms are golden brown and the tops are bubbling, 2 to 3 minutes. Flip and cook until the other sides are golden brown, about 2 minutes more. Repeat with more butter and the remaining batter. Serve warm with syrup and more lemon zest if you'd like.