Place pumpkin into the embers of a campfire. Cover with 1-2 inches of embers and roast for 3-4 hours until tender. Let cool.
Slice open the pumpkin. Remove the pulp and seeds. Scoop out roasted flesh and set aside. This should yield about 2 1/2 cups of pumpkin.
On a clean, smooth work surface, sprinkle flour. Using a potato ricer or food mill, add the cooked pumpkin to the flour.
Slowly add egg to the mixture and season with salt. Mix until just incorporated. Be careful not to overwork.
Using a dough scraper or knife, cut dough into 1/4s. One at a time, roll each quarter of the dough into a long roll about 1/2 - 3/4 inch in diameter. Slice into bite-size pieces.
Bring a large pot of salted water to a boil on a camp stove or campfire. Working in batches, cook gnocchi for 1-2 minutes until they float. Remove with a slotted spoon and drain excessive moisture.
While cooking gnocchi, add hazelnuts to a frying pan and gently toast. Remove from pan and set aside. Add butter to the pan and cook until golden brown. Add basil and nutmeg and season with salt and pepper.
Toss gnocchis in butter and parmesan cheese. Divide between bowls. Sprinkle with hazelnuts.
