Preheat your oven to 350°F (175°C) and grease an 8x8-inch baking dish.

In a medium saucepan, bring 1½ cups of water to a rolling boil. Add short-grain rice, reduce heat, cover, and simmer for 10-12 minutes until tender. Drain excess water.

In a large mixing bowl, combine whole milk, sweetened condensed milk, vanilla extract, cinnamon, nutmeg (if using), and salt. Whisk until smooth and creamy.

In a separate bowl, lightly beat the eggs and gradually whisk them into the creamy milk mixture until fully incorporated.

Spread cooked rice evenly in the greased baking dish. Sprinkle raisins or sultanas over the rice and pour the custard mixture on top.

Place the baking dish in a larger roasting pan. Fill the outer pan with hot water halfway up the sides of the baking dish.

Bake for 45-55 minutes, stirring halfway through. It's done when the top is golden and the pudding is set with a slight jiggle in the center.

Remove from the oven and let cool for 10-15 minutes before serving warm or chilled.