Trim the brisket: Place the brisket fat-side up.
Trim the fat cap to about 1/4 inch and remove any hard, waxy fat. Square off thin edges so they don’t dry out.
Mix the rub: In a bowl, combine 2 tablespoons kosher salt, 2 tablespoons coarse black pepper, 1 tablespoon garlic powder, 1 teaspoon onion powder, and 1 teaspoon paprika. Add 1 teaspoon brown sugar if you like a subtle sweetness.
Season generously: Rub a thin coat of oil on all sides.
Apply the seasoning mix evenly, pressing it into the meat. The brisket should be fully coated but not caked.
Rest before cooking: Let the seasoned brisket sit at room temperature for 45–60 minutes. This helps the rub adhere and takes the chill off.
Preheat the oven: Set to 275°F (135°C).
Place a rack in the lower third of the oven.
Prepare the pan: Line a large roasting pan or rimmed baking sheet with foil for easy cleanup. Place a wire rack inside if you have one. Pour 1/2 cup beef broth or water into the pan to add gentle moisture.
Start the cook: Place the brisket on the rack, fat-side up.
Roast uncovered for 3–4 hours. Mix 1/2 cup water with 1 tablespoon apple cider vinegar in a spray bottle and lightly spritz the brisket every hour after the first.
Wrap at the stall: When the internal temperature reaches about 160–165°F and the bark looks set and dark, wrap tightly in heavy-duty foil or butcher paper. Add a small splash of broth if the surface looks dry.
Continue low and slow: Return to the oven and cook until the internal temperature reaches 200–205°F and a probe slides in with little resistance.
Expect another 3–4 hours, depending on size and thickness.
Rest properly: Remove the wrapped brisket from the oven and place it in an empty cooler or on the counter, still wrapped, for at least 1 hour (up to 2). This step is crucial for juicy slices.
Slice against the grain: Unwrap and separate the flat and the point if you like. Slice the flat into 1/4-inch slices against the grain.
For the point, turn the meat 90 degrees and slice slightly thicker. Serve with the collected juices.