Bring the milk to the boil, then remove from the heat and add the butter; leave to cool until it reaches hand temperature; mix the flour, yeast, sugar and salt in a big bowl; mix the milk and the beaten egg into the dry ingredients with a wooden spoon
Tip the dough onto a surface that has been dusted with flour and knead for 10 minutes; lightly grease the mixing bowl with some oil and return the dough to the bowl; cover with a clean tea towel and leave to rise until it has doubled in size – up to 2 hours
Knock back the dough by gently kneading just five times to get the air out; cut the dough into 25 even pieces, using weighing scales if necessary and roll into balls; place on to lightly greased backing sheets and leave enough space between each one to grow
Cover the doughnuts again with a tea towel and leave to prove until doubled in size; preheat the oven to 190C/Gas5; half fill a roasting tray with boiling water and place in the base of the oven
Bake the doughnuts for 12-15 minutes until risen and dark golden; let them cool for a few minutes, then brush with the melted butter and roll them in the sugar; spoon some raspberry jam or chocolate ganache into a piping bag; make a hole in each doughnut, push in the nozzle and squeeze in a little jam or chocolate inside; serve warm
25 servings