1 1/2 cups cooked rice
2 cups milk, divided
1/4 teaspoon salt
2/3 cup golden raisins (optional)
1 egg, beaten
1/3 cup white sugar
1 Tablespoon butter
1/2 teaspoon vanilla extract
Combine cooked rice, 1 1/2 cups milk, and salt in a saucepan over medium heat; cook and stir until thick and creamy, 15 to 20 minutes.
Stir remaining 1/2 cup milk, golden raisins, beaten egg, and white sugar into the rice mixture; stirring continually.
Continue cooking until egg is set, 2 to 3 minutes.
Remove saucepan from heat; stir butter and vanilla extract into the pudding.