Heat oil in a large saucepan over medium-high heat. Add onion, bell pepper, and garlic. Cook until softened, stirring occasionally, for 6 minutes. Add in the chiles, chili powder, cocoa, cumin, cinnamon, sugar, and salt. Stir to combine and cook about 1 minute. Add ground beef and cook, breaking it up with a spoon, until browned, about 8 minutes.