In a bowl, dissolve yeast in warm milk. Add the butter, sugar, pumpkin, 2 eggs, salt and 3 cups flour. Beat until smooth. Stir in enough remaining flour to form a soft dough. Turn onto a lightly floured surface; knead until smooth and elastic, 6-8 minutes. Place in a greased bowl, turning once to grease top. Cover and let rise in a warm place until doubled, about 1 hour.
Punch dough down. Turn onto a lightly floured surface; divide in half. Shape each portion into 12 balls. Roll each ball into a 10-in. rope; tie into a knot and tuck ends under. Place 2 in. apart on greased baking sheets. Cover and let rise until doubled, about 30 minutes.
In a small bowl, beat water and remaining egg. Brush over rolls. Sprinkle with sesame or poppy seeds if desired. Bake at 350° for 15-17 minutes or until golden brown. Remove from pans to wire racks.