In a large pot, over medium-high heat, combine melted butter and sugar. Mix until combined and then slowly pour in milk. Add semolina and vanilla. Cook for about 5 minutes, stirring regularly.
1/4 cup melted, unsalted butter, (meaning you should end up with 1/4 cup after it is melted), 1/2 cup sugar, 1 liter 2% milk (you can use lactose free milk if you need to), 1/2 cup fine ground durum wheat semolina, 1/4 teaspoon powdered vanilla