Put oven rack in middle position and preheat oven to 325°F.
Cook onion in oil in a 4- to 5-quart heavy pot over moderately high heat, stirring, until golden, about 6 minutes. Add garlic and cook, stirring, 1 minute. Stir in coffee, zest, cinnamon stick, and brown sugar, then bring to a simmer. Sprinkle beef all over with salt and pepper, then add to pot. Transfer pot to oven and braise, tightly covered, until meat is very tender, 3 1/2 to 4 hours.