Rinse the rice. Place the rice in a fine-mesh strainer and rinse under cool water until the water runs mostly clear. This removes excess starch that can make the pudding gluey.

Warm the dairy. In a medium, heavy-bottomed saucepan, add the milk, cream (if using), cinnamon, and salt. Heat over medium-low until steaming but not boiling, stirring occasionally to prevent scorching.

Add the rice. Stir in the rinsed rice. Bring the mixture to a gentle simmer, then reduce heat to low. Cook uncovered, stirring every few minutes so the rice doesn’t stick. Keep the heat low—gentle bubbling is what you want.

Simmer to creamy. Cook for 25–30 minutes, or until the rice is tender and the mixture has thickened to a loose pudding. It will continue to thicken as it cools. If it gets too thick too soon, stir in a splash more milk.

Sweeten and flavor. Stir in the sugar substitute and vanilla. Taste and adjust sweetness. Different sweeteners vary in intensity, so add gradually.

Temper the egg (optional but luxurious). In a small bowl, whisk the egg. Ladle in a few spoonfuls of the hot pudding while whisking constantly to warm the egg without scrambling. Pour the egg mixture back into the pot, whisking steadily. Cook 1–2 more minutes until slightly thicker and glossy.

Rest and set. Remove from heat. Let the pudding sit for 5 minutes, then give it a final stir. If using zest or raisins, fold them in now. The texture should be creamy and spoonable.

Serve warm or chill. Spoon into bowls and dust with more cinnamon. For a classic chilled pudding, cover and refrigerate 2–3 hours. If it thickens too much after chilling, stir in a splash of milk to loosen.