01 - Combine rice, whole milk, heavy cream, lemon peel, cinnamon stick, and salt in a medium saucepan. Bring to gentle simmer over medium heat, stirring occasionally.
02 - Reduce heat to low and cook for 25-30 minutes, stirring frequently, until rice is tender and mixture thickens noticeably. Remove lemon peel and cinnamon stick.
03 - Stir in sugar, butter, and vanilla extract. Continue cooking for 2-3 minutes until sugar completely dissolves.
04 - Whisk egg yolks in separate bowl. Gradually add several spoonfuls of hot rice mixture to yolks while whisking continuously to temper eggs.
05 - Return tempered yolks to saucepan. Cook over low heat, stirring constantly, for 2-3 minutes until mixture slightly thickens. Do not allow to boil.
06 - Pour custard into individual ramekins or large serving dish.
07 - Mix 2 tablespoons granulated sugar with ground cinnamon. Sprinkle evenly over custard surface.
08 - Let rice custard cool to room temperature. Serve warm or refrigerate for chilled presentation.