Sift the flour and salt into a large bowl. Stir in 50g sugar and yeast.
Make a well in the flour. Add the beaten egg. Add milk and mix into a dough.
On a floured board, knead the dough until soft - about 5 minutes. Divide the dough into 20 portions and roll into balls. Place on a greased baking tray, cover with clingwrap or a damp teatowel and leave the dough to double in size in warm place.
Bake in a 220 degree celcius oven for 12 - 15 minutes or until well risen and browned. Cool slightly.
Combine extra sugar and cinnamon.
Make a small incision in the doughnut and fill with a teaspoon of jam (a syringe or narrow spoon works well). Brush lightly with water and roll into the cinnamon sugar.