Preheat the oven to 400 degrees F. Place the nuts, peppers, and onions on a baking sheet. Drizzle with 1 tablespoon olive oil. Roast for 10 to 15 minutes. Remove from the oven and peel, seed and chop the peppers. In a food processor, combine the nuts, peppers, onions, chili powder, cumin, salt, tamarind paste, 1 tablespoon dark cane syrup, vinegar and olive oil. Puree until creamy, stopping once to scrape the sides of the bowl. Turn the sauce into a saucepan. Whisk in the chicken stock and cream. Bring the sauce up to a boil and reduce to a simmer. Cook for 2 minutes. Remove from the heat and keep warm.
Serve the mole sauce with the tamales.