Preheat the oven to 200°C (approximately 375°F). Butter 4 small soufflé dishes carefully and sprinkle with sugar.
Separate the eggs and beat the yolks with 50 grams (approximately 2 tablespoons) of sugar until light and creamy. Pass the well-drained quark through a sieve and stir with the Limoncello into the egg yolk mixture. Beat the egg whites until stiff, gradually sprinkle in the remaining sugar. Fold 1/3 of the egg whites into the egg yolk mixture, sift the flour over the top and fold together, followed by the rest of the egg whites.
Fill the ramekins 3/4 full with the batter.
Bake the soufflés in the preheated oven for 10-15 minutes. Dust with powdered sugar and serve immediately.