01 - Combine 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 simmer for 25–30 minutes, stirring frequently, until rice is tender and mixture has thickened to a creamy consistency. Remove and discard lemon peel and cinnamon stick.
03 - Stir in granulated sugar, butter, and vanilla extract. Continue cooking for 2–3 minutes, stirring until sugar completely dissolves and butter is incorporated.
04 - Whisk egg yolks in a separate bowl. Gradually ladle 2–3 spoonfuls of hot rice mixture into yolks while whisking continuously to gently raise temperature without curdling.
05 - Return tempered yolks to saucepan. Cook over low heat, stirring constantly, for 2–3 minutes until mixture slightly thickens. Do not boil or eggs may scramble.
06 - Pour custard evenly into individual ramekins or a 9-inch baking dish for family-style serving.
07 - Mix remaining 2 tablespoons sugar with ground cinnamon. Sprinkle evenly over custard surface.
08 - Let custard cool to room temperature, approximately 1 hour. Serve warm or refrigerate for at least 2 hours for chilled servings.