Place the rice, coconut milk, milk, butter, sugar, nutmeg, vanilla pods (if using) and cinnamon stick into a non-stick saucepan. Bring the mixture to a simmer, reduce the heat and simmer gently, covered but stirring occasionally for 35 minutes, or until the rice has absorbed the liquid. Stir in the vanilla extract (or vanilla seeds if using), the heavy cream and any other flavoring ingredients you choose. Loosen to the desired consistency.