01 - Combine the rice, whole milk, heavy cream, lemon peel, 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 often, 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, unsalted 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 add a few spoonfuls of the hot rice mixture to the yolks while whisking continuously to temper them and prevent curdling.
05 - Return the tempered yolks to the saucepan and cook gently over low heat, stirring constantly for 2–3 minutes until the mixture thickens slightly. Do not allow it to boil.
06 - Pour the custard into individual ramekins or a large serving dish, distributing evenly.
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 before serving. Serve warm for a comforting dessert or chilled for a refreshing treat.