Mix the milk, sugar, yeast, egg and flour together until it comes together into a dough – don’t worry if it isn't smooth. Cover and leave to prove for 1 hr at room temperature, then stir in the melted butter with a wooden spoon or spatula. Cover again, transfer to the fridge and leave to prove overnight.

The next day, remove the dough from the fridge and leave to come to room temperature for 1 hr before frying. Fill a wide, deep frying pan no more than a third full with oil and heat until a pinch of dough starts to sizzle as soon as it's dropped in. Fry 3-4 dessert-spoon-sized scoops of dough at a time until browned, about 1-2 mins, then flip over and repeat on the other side. Alternatively, spoon the mixture into a piping bag, snip off the end and pipe directly into the hot oil. Remove the cooked fritters to a plate lined with kitchen paper to drain, and repeat until all the dough has been used. If needed, keep warm in a low oven while you fry the rest.

Tip the hot fritters into a heatproof bowl, sprinkle with cinnamon sugar and gently toss to coat. Serve hot.