Roast the squash: Preheat oven to 425°F. Rub the inside of the pumpkin or squash with a light coating of olive oil and season with salt and pepper; place cut side down on a lightly oiled rimmed baking sheet. Place the bell pepper and the poblano in a small heavy casserole dish, coat lightly with olive oil and season with salt and pepper. Place the pumpkin or squash and peppers in the oven and roast. The pumpkin or squash is done when a knife meets no resistance when inserted into the flesh and the edges are caramelized, about 45 minutes to 1 hour. The peppers are done when they are very soft and the skins are well browned, about 45 minutes to 1 hour. Turn the oven up to 450°.
Let the cooked pumpkin or squash rest until it is cool enough to handle. Place the cooked peppers in a bowl and cover with plastic wrap; cool until you can pick them up with your hands.
Scoop the pumpkin or squash flesh into a large heavy-bottom soup pot. Add the onions, garlic, chicken stock, chile powder, cinnamon and chipotle powder. Simmer over medium heat until the onions and garlic are soft.
Allow to cool slightly then carefully purée in batches in a blender or food processor. Return the soup to the pot and season to taste with salt and pepper.
Meanwhile, lay the slices of ham on a sheet pan lined with parchment paper. Watching it carefully, bake the ham slices until they crisp and just begin to brown, about 6 to 8 minutes. Cool on the sheet pan. The ham will get crispier as it cools.
While the soup reheats, peel and seed the peppers (using rubber gloves to protect your hands, if necessary). Slice into thin strips. Pour the can of hominy into a small pot and heat until simmering and warmed through.
To serve the soup, place a heaping tablespoon of the drained hominy into a warmed soup bowl. Top with a few strips of the roasted pepper and one slice of the crispy ham. Ladle soup into bowls; garnish with chopped cilantro and a drizzle of roasted pumpkin seed oil.