01 - Combine the rice, whole milk, heavy cream, lemon peel strips, cinnamon stick, and salt in a medium saucepan. Place over medium heat and bring to a gentle simmer, stirring occasionally to prevent sticking.
02 - Reduce heat to low and simmer for 25–30 minutes, stirring frequently, until the rice is tender and the mixture has thickened to a creamy consistency. 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 2–3 spoonfuls of the hot rice mixture into the yolks while whisking continuously to gently warm them without curdling.
05 - Pour the tempered yolks back into the saucepan. Cook over low heat, stirring constantly, for 2–3 minutes until the custard thickens slightly. Do not allow the mixture to boil.
06 - Pour the custard evenly into individual ramekins or a large serving dish.
07 - Mix the remaining 2 tablespoons granulated sugar with the ground cinnamon. Sprinkle evenly over the surface of the custard.
08 - Allow the rice custard to cool to room temperature, then refrigerate if serving chilled. Serve warm or cold according to preference.