Mix together all the dry ingredients well, add beaten egg, and butter, mix it too. Then bind using warm water to form a soft dough and let it rise. Roll into 1/2" roti and cut into donut shapes. Keep on flour dusted paper on a thaal or use greased trays. Let it rise for half an hour then deep fry till golden brown colour. If you are using castor sugar for glaze, do glaze as soon as you fry them, sprinkle castor sugar using sieve. If you are glazing wait until they are cold.
When donuts are fried and cooled down. Take a piping bag fill it with nutella and use the long nozzle with a smoll hole in it. From any side of a donut insert the nozzle and press in nutella you will feel the fill in. Dont exert more just a little. Glaze with sugar or can use glaze and keep on platter.