Rinse 100g of rice under cold water to remove excess starch.
In a large, heavy-bottomed pot, combine 1 liter of whole milk, 1 piece of lemon peel, 1 piece of orange peel, and 1 cinnamon stick.
Bring to a gentle boil over medium heat, stirring frequently. Add the rinsed rice
Reduce heat to low and simmer uncovered, stirring occasionally, for 20 minutes.
Add 70g of sugar and 10g of butter. Stir well until sugar is dissolved and butter is melted.
Continue simmering for another 10-15 minutes or until the rice is tender and the mixture has thickened to a creamy consistency.
Remove from heat and discard the lemon peel, orange peel, and cinnamon stick.
Serve warm or chilled, sprinkled with cinnamon powder.