Dissolve yeast in a large bowl with ½ cup warm water. Let stand until bubbling, about 5 minutes. Add eggs, shortening, pumpkin, milk, sugars, pudding mixes, salt and 6 cups flour. Beat until smooth. Slowly stir in up to 1 more cup of flour until soft dough forms. (Dough will be sticky).
Spread ½ cup flour on a flat surface. Knead dough for 6-8 minutes, until smooth and elastic. Place in a greased bowl, turning to grease top of the dough. Cover and place in a warm spot. Let rise for about 1 hour or until doubled in size.
Punch dough down and divide in half. Roll each into a 12x8 rectangle. Brush with melted butter. Mix together your brown sugar and pumpkin pie spice; sprinkle over dough.
Start rolling with a long side (jelly-roll style); pinch seams to seal. Cut each roll into 12 slices. Cut side down, place into 2 greased 9x13-in. pans. Cover and let rise for about 30 minutes or until doubled.
Bake for 22-28 minutes at 350°. Rolls should be golden brown. Combine your water, butter and pumpkin pie spice In a small bowl. Add powdered sugar and vanilla and beat until smooth. Spread over warm rolls.