Put in a mixing bowl the ricotta with the flour, three tablespoons of sugar, eggs and a pinch of salt.
Work with a long wooden spoon, then add the lemon zest , liqueur and cinnamon.
Stir until mixture is smooth and homogeneous , let it rest for five minutes.
Put the oil in a frying pan and , as it becomes hot , pour spoonfuls of the mixture , forming round fritters.
Brown them on fire not too lively.
Once ready , remove from the oil the fritters with a skimmer, roll them in paper towels to absorb the oil and place in a dish sprinkling with powdered sugar.
Serve warm if possible.