I decided to whip out my trusty slow cooker and was determined to use only ingredients in the house and make something that was still finger licking worthy.
Combine the sugar, 2 tbs adobo sauce, cumin, paprika, 1 teas salt, and 2 teas black pepper in a bowl. Stir to combine. Using a fork, prick the brisket all over.
Slather in the sugar mix and wrap in plastic wrap. Let the flavors mingle in the fridge over night. When ready to cook, unwrap brisket and place in slow cooker.
Microwave the onions, tomato paste, garlic, oil, chili powder, and remaining 2 tbs adobo sauce in for 1 minute increments, stirring as needed, until the onion is soft.
Add the water and cover and cook on high for 5 to 7 hours or on low 9 to 11 hours. Carefully transfer brisket to a cutting board, tent with foil, and let rest for 20 minutes.