First, make sure your sourdough starter is active and bubbly. If it isn’t, feed it again and set aside. You can check it's ready by putting a tsp of the starter in warm water – if it floats, it's ready to use. Tip the starter, most of the egg (reserving a little if you want to glaze it later), 1 heaped tsp salt and all the other ingredients except the butter, into a bowl. Mix with your hands to form a rough dough, making sure all the flour from around the bowl is mixed in. You can do this in a tabletop mixer with a dough hook, if you prefer. Leave the dough covered with a damp cloth for 30 mins.

Tip the dough onto a clean surface and knead for 15-20 mins by hand, or 5-8 mins in a mixer with a dough hook on a medium speed, until springy and glossy. Use your hands to work the butter into the dough – this will take about 5 mins. At first, it will look like it’s not coming together, but keep working the dough through your fingers and it will become smooth and glossy. Form the dough into a ball and put back in the bowl. Cover and leave in a warm place for 2-3 hrs until nearly doubled in size. Your dough is now ready to use to make enriched breads, from cinnamon rolls and babka to sweet buns and doughnuts.

To make two tin loaves, tip the dough onto a floured work surface and knead briefly, then spilt into two. Shape the dough into two rounds, then leave for 10 mins. Form the rounds into rough oblongs, then sit them in two 900g loaf tins. Leave the loaves out for another 2-3 hrs or in the fridge overnight until the dough has doubled in size again. For a plaited loaf, place the dough in the fridge for an hour to stiffen, then split into three, roll out into equal sized lengths of dough and neatly plait together. Lift the plaited loaf onto a lined baking tray, cover and leave at room temperature for another 2-3 hrs or in the fridge overnight, until the dough has doubled in size.

To bake, heat the oven to 200C/180C fan/gas 6. Brush the top of the loaves with the reserved beaten egg and bake for 30-35 mins until golden brown. Leave the loaves in the tins to cool a little, before transferring to a cooling rack.