01 - Combine the rice, whole milk, heavy cream, lemon peel strips, cinnamon stick, and salt in a medium saucepan. Bring to a gentle simmer over medium heat, stirring occasionally to prevent sticking.
02 - Reduce heat to low and cook for 25–30 minutes, stirring frequently, until the rice is completely tender and the mixture has thickened considerably. Remove and discard the lemon peel and cinnamon stick.
03 - Stir in the granulated sugar, butter, and vanilla extract. Continue cooking for 2–3 minutes, stirring until the sugar has completely dissolved.
04 - Whisk the egg yolks in a separate bowl. Gradually ladle small amounts of the hot rice mixture into the yolks while whisking continuously to temper them and prevent curdling.
05 - Pour the tempered yolks back into the saucepan. Cook over low heat, stirring constantly, for 2–3 minutes until the custard coats the back of a spoon. Do not allow the mixture to boil.
06 - Pour the custard evenly into individual ramekins or a large serving dish. Smooth the surface with a spoon.
07 - Mix the remaining granulated sugar with ground cinnamon in a small bowl. Sprinkle the mixture evenly over the surface of the custard.
08 - Allow the rice custard to cool completely to room temperature. Serve slightly warm or thoroughly chilled, according to preference.