In a large saucepan combine the milk, rice, raisins, sugars, and cinnamon. Bring to a bowl. Cover with a lid and reduce to a simmer. Simmer for 20-25 minutes or until rice is tender. Stir occasionally to prevent sticking.
In a small bowl whisk together the cream and egg. When the rice is tender temper the egg mixture by slowly whisking in 1 cup of the hot rice mixture. Then whisk the temper egg mixture into the large pot of cooked rice. Cook on low until thickened (about 2 minutes).
Remove from heat and stir in butter and vanilla. Serve warm or chilled.