Preheat your smoker to 225°F using a clean-burning hardwood like oak or hickory.
Trim the excess fat cap from the beef brisket to about one-quarter inch thickness and pat the meat dry.
In a small bowl, whisk together the smoked paprika, garlic powder, onion powder, chipotle powder, sea salt, and black pepper.
Apply the spice rub generously to all sides of the brisket, pressing it into the meat to ensure it adheres.
Place the brisket on the smoker and cook until the internal temperature reaches 165°F and a dark bark has formed.
Wrap the brisket tightly in butcher paper and return it to the smoker until the internal temperature reaches 203°F.
Remove the meat from the smoker and let it rest in a cooler or room temperature for at least 45 minutes to retain juices.
While the meat rests, simmer the tomato paste, maple syrup, one tablespoon of apple cider vinegar, and water in a pan until thickened.
Chop the rested brisket into bite-sized pieces and toss with the warm sweet and smoky sauce.
Combine the shredded cabbage with the remaining vinegar and yellow mustard to create a bright, crunchy slaw.
Lightly toast the sprouted grain bun and pile the chopped brisket high, finishing with a scoop of slaw.