make the batter
In a bowl, stir to combine probiotic yogurt, eggs, sugar, vanilla sugar, baking powder, and lemon zest. Add all-purpose flour and a pinch of salt and mix well using a whisk to get a smooth batter. Set aside for 10 minutes.
Place a small pot or saucepan with oil over medium-high heat. When the temperature of the oil reaches 170°C or 340 °F, start frying. Carefully drop a teaspoon of the batter into the hot oil. Repeat the process, but don't overcrowd the pan; work in batches. Fry for about 4 - 6 minutes or until the fritters are golden brown. Shake the pan from time to time.
Transfer the sweet fritters to a plate lined with paper towels, then serve sprinkled with icing sugar.