Add olive oil and onion to large pot and cook over medium heat till onion begins to soften, about 3 minutes. Add garlic, ground turkey, 1 tsp chili powder, 1 tsp cumin, and continue to cook till turkey is browned, stirring frequently. Add the bell pepper, pumpkin puree, diced tomatoes, corn, and water and stir till smooth. Add all remaining spices and stir. Reduce heat to low and cook 1 hour.