Boil the Rice Boil rice in a pot until tender and the water evaporates.
Add Milk Add whole milk and sweetened condensed milk. Cook for 10 to 15 minutes.
Sweeten Add sugar and continue to cook for an additional 5 to 10 minutes.
Temper and Add Eggs Incorporate eggs by warming them with a portion of the hot rice mixture first. Beat the eggs and gradually add them to the pot, stirring constantly to prevent scrambling.
Season Introduce vanilla extract, butter extract, cinnamon, and nutmeg. Cook and stir for 3 to 5 minutes.
Set and Cool Transfer the mixture to a baking dish. Optionally, top with extra cinnamon. Let it sit for 2 hours to set.
Serve If you enjoy it cold, let it sit for the initial 2 hours and then refrigerate for an hour or more.