Put the milk and a pinch of salt in a small saucepan and heat gently over a medium heat until it just comes to the boil.
Once it starts to boil, gradually whisk in the cream of rice cereal, stirring constantly to prevent lumps.
Reduce the heat to low and simmer for 3–5 minutes, stirring occasionally, until the mixture is thick and creamy.
Take the pan off the heat and stir in the caster sugar until it has dissolved.
If you’re using it, stir in the vanilla extract.
Serve it hot, with a knob of butter, a dusting of cinnamon or some fresh berries, if you like.