In a bowl, sift together flour, salt, baking powder and baking soda

In a separate bowl, mix together icing sugar and butter until smooth, then add in the egg and mix until light and fluffy.

Add in the vanilla extract, and lightly mix.

Add in the dry ingredients and milk in two portions, beginning and ending with flour

Mix well then, then knead for about 3 minutes, put dough in the fridge for 10-15 minutes.

Remove from the fridge, let it sit 5 minutes, then roll out on a floured surface with a floured rolling pin.

Heat oil over medium heat until 180°c then deep fry the donuts, giving each side atleast one minute.

Drain off excess oil, then serve.