Sprinkle brisket with salt and place it on a cooling rack. Place the in the fridge, uncovered, overnight.
Once chilled, begin preheating your pellet smoker to 225°F. Then, spread the tallow around the brisket and rub.
Combine pepper, remaining salt, paprika, and garlic powder, in a bowl and whisk well.
Pour the rub over the entire brisket and rub it on until every portion is covered.
Place apple cider vinegar in a spray bottle. Place the brisket in the smoker for 4-6 hours, spritzing with the vinegar every hour.
Remove the brisket and tightly wrap it in tin foil. Place it back in the smoker for another 4-6 hours.
Allow the brisket to rest for 10 minutes and no more than 2 hours. Slice against the grain, serve, and enjoy!