In a medium, heavy-bottomed saucepan, add milk, rice and salt. Cook the rice at a low simmer until the rice is tender, do not boil. Once you achieve "simmer," the rice should take around 20 to 30 minutes to be ready, depending on your cooker. Taste the rice to make sure it is tender. Remember to keep stirring so the rice doesn't stick to the bottom. Once the mixture has cooked, remove from heat and add sugar, vanilla, raisins and egg yolks. Keep stirring to incorporate all of the flavors, then let it sit for about 10 minutes. The sugar and vanilla will infuse very quickly, giving a flowery aroma. Add the heavy cream and butter, mixing them well together in the saucepan. Spoon into ramekins or individual serving bowls. Rice pudding can be served warm, room temperature or chilled. This particular recipe benefits from setting overnight in the refrigerator. Sprinkle with cinnamon, if desired.