Start the dough: Melt the butter in the microwave or on the stovetop. Stir in the milk, sugar, and salt. Add the milk mixture and 1 cup of the flour over the yeast. Stir until this comes together into a loose, lumpy batter. Add another 4 1/2 cups of flour, reserving the remaining cup if the dough is sticky during kneading. Stir until a floury, shaggy dough is formed.