Mix the flour with the salt and syrup, and gently rub in the butter until combined. Stir in the yeast. Warm the milk in the microwave for a few seconds until warm to the touch, the pour into the batter with the egg. Knead by hand for at least 5 mins, or in a stand mixer fitted with a dough hook for 3-4 mins. Cover the bowl and allow the dough to rest for at least an hour.

Towards the end of the rising time, make the ganache: melt the chopped chocolate in the microwave until just melted. Heat the cream until just simmering, then pour into a cold bowl and whisk in the melted chocolate until it is thick and glossy. If it looks like it is starting to split, stir in a little more cold cream. Set aside. Line a baking tray with baking paper.

Punch the risen dough down and divide into 10 equal sized balls. Use you thumb to push a hole into the middle of the dough ball, taking care not to poke all the way through. Fill the hole with a teaspoon of so of the ganache and pull the dough over the ganache to cover it as best you can, then place on the lined baking tray, seam side down, smooth side up. Repeat with the rest of the dough. You should have some ganache left at the end - put this aside and keep for dipping the doughnuts into later.

Turn the oven on to 190C/375F/gas 5. Cover the doughnuts with a tea towel and leave to rise for 20-30 mins while the oven preheats. Brush with a little melted butter, if you like, then bake for 10-12 mins, until puffed up and golden. Brush with the melted butter while still warm and dust with the sugar (if using) and cinnamon. Best served with with the ganache for dipping, but they are pretty great cold, too!