Turn out onto a lightly floured surface and knead until smooth, about 5 minutes, adding flour if needed (you can do this whole process in the bowl of a stand mixer, fitted with a dough hook).

Place the dough in a lightly oiled bowl, cover with a clean, damp cloth, and set aside in a warm place for 45 minutes or until doubled in size.

Knead the dough on a lightly floured surface. Roll out to 1cm thick and use a 5.5cm round cutter to cut 20 rounds from the dough.

Place the rounds on a baking tray lined with baking parchment, cover with a dry clean tea towel, and set aside for 20 minutes or until risen.

Place the oil and a sugar thermometer in a large, deep saucepan over medium heat until temperature reaches 160°C alternatively use a deep fat fryer.

Cook the doughnuts, in batches, for 1–2 minutes on each side or until golden. Drain on absorbent paper for a couple of seconds, and then immediately roll in caster sugar.

Using a small knife, make a small slit on the side of the doughnut, then using a piping bag fitted with a small nozzle push about a tablespoon of jam into the doughnuts.