Dissolve yeast and 1 teaspoon sugar in warm water; stir well. Let stand 5 minutes or until bubbly.
Combine remaining sugar, eggs, shortening, milk, and salt in a large mixing bowl; stir until sugar and salt are dissolved. Add yeast mixture, stirring well. Stir in enough flour to make a soft dough.
Place dough in a greased bowl, turning to grease top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in bulk. Punch dough down, and let rest 5 minutes.
Lightly grease muffin pans. Shape dough into 2-inch balls; place 1 ball in each muffin cup. Cover and repeat rising procedure 45 minutes or until doubled in bulk. Bake at 400° for 12 minutes or until lightly browned. Brush with melted butter.