Preheat the oven to 230 C / 210 Fan / Gas 8 with a shelf just above the middle position.

Combine the milk and water in a jug.

Stir together the flour and salt then sift into a bowl.

Make a well in the middle of the flour then crack in both eggs.

Using a whisk, start beating the eggs while gradually drawing in some of the flour. Gradually add about half the milk and water while drawing in the remaining flour: if you need to, use a silicone spoon or spatula to scrape down the sides of the bowl.

When you have a smooth batter, whisk in the remaining milk and water.

Transfer to a jug for easier pouring.

Can be made in advance and put in the fridge for an hour.

Put the butter and oil in a deepish baking tin that's approximately 20 x 30 cm (a tin with a smaller base will give a thicker pudding that may need longer cooking) and place in the oven to heat.

Halve the plums, remove the stones, then cut into quarters (or sixths if they are large).

Stir together the sugar and cinnamon.

When the butter and oil are sizzling hot, evenly space the prepared plums in the tin and sprinkle them with the sugar and cinnamon.

Pour the batter into the tin and immediately put in the oven.

Bake for 25 minutes* or until risen and cooked all the way through: the fruit should be soft, and the middle of the batter should be fluffy, the edges crispier and darker.

* After the first 20 minutes, check that the top isn't browning too much. Turn the temperature down to 220 C / 200 Fan / Gas 7 for the final 5 minutes if necessary.

Cut into slices and serve with pouring cream, custard or ice cream.

If not eaten straight away it will not be as fluffy, but still tastes good.

Can be stored in the fridge for 2 days and reheated in a microwave.