Real pumpkin, 1-2 per bbl in the mash. Pre-cook till mushy
Real spices- look up pumpkin pie recipies for type/ratios. add about 1oz/bbl total to the boil for 20-15 mins.
Keep the color light in the grist and you will get a cool orange color from the caratine.
Hop lightly- under 10 IBU, 12-13 OG. let the spices and pumpkin dominate.