Preheat the oven to 425.

Slice the pumpkin in half lengthwise. Scoop out the seeds and set aside.

Rub olive oil all over inside and outside of pumpkin and place cut side down on a cookie sheet.

Roast for about 40 minutes, or until knife slides easily into the pumpkin.

Allow to cool completely, then peel off the skin.

Place the flesh in a food processor and pulse until fairly smooth.

In a large bowl mix all dry ingredients well.

Drop pieces of butter into the dry ingredients and using a pastry cutter, cut in the butter until it resembles crumbs.

Add water to egg and add egg mixture to dry ingredients.

With your hands mix the pastry gently until it is all absorbed and form into a disc. Place the bowl in the fridge for about 5 minutes.

Once cool, place the disc between two sheets of wax paper powdered with arrowroot. Using a rolling pin, roll dough to desired shape.

Gently loosen wax paper from pastry on both sides. Remove one side and use the other to turn and place into pie shell.

Poke with fork all around.

Mix all ingredients in a large bowl. Pour into pie shell.

Bake at 400 for 15 minutes.

Reduce heat to 350. Bake for additional 40 to 50 minutes (covering pie crust edges with foil if getting to brown) until a knife come out clean.

Serve with homemade whipped cream.