Combine 2 cups cooked long grain rice, 3/4 of the2 cups whole milk (save the remaining milk for adding later), and a pinch salt in a saucepan over medium heat.
Cook, stirring occasionally until thickened, around 10-15 minutes. You don’t want it to boil (or stick to the bottom of the saucepan, so keep it moving!)
Reduce the heat to medium-low, and stir remaining milk, 1 cup golden raisins, 1 egg(beaten), and 1/3 cup white sugar in, stirring.
Continue cooking 2 to 3 minutes – to allow the egg to cook and blend into the pudding.
Remove saucepan from heat; stir 1 tablespoon butter and 1 teaspoon vanilla extract into the pudding.