Chinese Cocktail Buns
1 cup all-purpose flour, or more if needed 1 cup finely grated fresh coconut 1 cup milk 1 egg 1 egg, beaten 1 tablespoon active dry yeast 1 tablespoon sesame seeds, for garnish 2 ½ cups all-purpose flour ¼ cup softened butter ½ cup all-purpose flour ½ cup nonfat dry milk powder ½ cup white sugar ⅓ cup white sugar