In large bowl, stir 4 cups flour, 1/4 cup sugar, the yeast, salt, milk and 1/2 cup melted butter until well mixed. On lightly floured surface, knead dough 5 to 6 minutes, adding additional flour as needed, until smooth and no longer sticky. Grease large bowl with shortening or spray with cooking spray. Place dough in bowl, turning dough to grease all sides. Cover and let rise in warm place 30 to 40 minutes or until dough has doubled in size.