Use any enriched yeast risen bread dough.
1lb strong plain flour
teaspoonful of dried yeast
1 egg beaten
enough warm water to make the egg up to half a pint.
Dissolve the yeast in half the warmed water
stir in a spoonful of sugar, and wait until it is frothy.
Add the yeast mix, the rest of the water and the beaten egg to your flour and knead to a smooth and elastic dough.
Cover with oiled cling film and leave to rise until double in size.
break off pieces and cook in doughnut maker.
Drain, and roll in sugar.
You can roll your dough into sausage shapes and curl them around before letting it rise if you want donuts with holes, or if you want them filled with jam, take a ball of arisen dough, make a dent in it with your thumb, add a bit of jam, and close the dough over the jam.
Then rise and cook as before.