Rinse the short-grain rice under cold running water in a strainer until the water runs mostly clear. Drain well.
Combine rinsed rice and 2 cups of water in a medium saucepan over medium-high heat. Bring to a boil, stir once, then reduce to medium-low and simmer uncovered for 8 to 10 minutes until most of the water is absorbed and the rice is halfway cooked.
Pour in the whole milk. Add the cinnamon stick, lemon zest strip, and salt. Raise heat to medium, stirring as the milk heats, and bring to a gentle simmer.
Reduce heat to low. Cook uncovered, stirring every 3 to 4 minutes, for 20 to 25 minutes until the pudding reduces, thickens, and coats the back of a spoon.
Remove and discard the cinnamon stick and lemon zest. Stir in the granulated sugar and cook over low heat for 2 to 3 minutes, stirring continuously, until fully dissolved.
Serve warm in bowls dusted with ground cinnamon, or transfer to containers, press plastic wrap onto the surface, and refrigerate until cold. Stir in a splash of milk before serving if chilled.
