Preheat your smoker or oven to 225°F (107°C).
Trim any excess fat from the brisket flat, leaving a thin layer for moisture.
Rub the brisket evenly with olive oil, sea salt, black pepper, and garlic powder.
Place the brisket in the smoker or oven and cook until the internal temperature reaches 190°F (88°C).
In a small bowl, whisk together the tomato paste, apple cider vinegar, maple syrup, and smoked paprika to create the glaze.
Brush the glaze over the brisket and continue cooking until the internal temperature reaches 195-200°F (91-93°C).
While the brisket finishes, roast the halved Brussels sprouts at 400°F (204°C) for 20 minutes until tender and charred.
Remove the brisket from the heat and let it rest for at least 15 minutes before slicing against the grain to serve.