Heat the oil in a medium sauce pan over medium heat. Add in the flour, then quickly whisk together until combined. Add in the chili powder, cumin, garlic powder, oregano, salt, cinnamon and cayenne pepper and toast until fragrant, about 1 minute.
Add in the tomatoes and water, then bring to a simmer. Cook over medium heat until thickened, about 5-7 minutes, whisking often. For a thinner sauce, puree with an immersion blender or place the mixture in a blender and puree until smooth.