Press ricotta through a food mill, potato ricer or a fine mesh strainer into a large bowl. Put the eggs, sugar and vanilla in another bowl and whisk til pale and light. Fold into ricotta.
Sift flour with baking powder and salt into a bowl, then fold it into the cheese and egg mixture.
Heat vegetable oil in a deep fryer to 375. Have a tray lined with paper towels and a slotted spoon or strainer at the ready.
drop level tablespoons of mixture into hot oil in batches of 6. fry for 2 to 3 minutes or til puffed and deep brown all over. You may have to turn them in the oil. Drain and serve at once, dusted with powdered sugar. Serves 4 to 6