Arroz Con Leche (Rice Pudding)

So this is something that I really didn't like as a kid. But for some reason since I got older I have made it a few times just because I am in the mood for it. It is a great way to use left over plain white rice for your dinner. My family liked it so I am sharing it with you.
Enjoy!

1 1/2 cups rice
1 large egg
2 1/2 cups milk
1/2 cups sugar
2 Tbs vanilla
2 tsp cinnamon
2 Tbs butter (unsalted)
3 Tbs sweetened coconut flakes (opt)
3/4 cup raisins (opt)

In a saucepan mix rice and egg. Add remaining ingredients except raisins. On low heat for 5 minutes continuously whisk mixture. Raise temperature to medium and continue to whisk for another 10 minutes. Raise temperature to high-medium/low high setting. Continue to whisk until mixture starts to thicken. Remove from heat and add raisins. Takes about 20-30 minutes till mixture thickens. Remember to keep whisking mixture or you will had scramble egg pieces in pudding also while at higher temperatures if left standing the mixture will burn as well boil over and make a mess. It is an easy recipe. Mostly just requires patience until it is cooked. Hope you like it as much as my family did.