In a small mixing bowl, combine the brown sugar, paprika, garlic powder, onion, powder, sea salt, black pepper, mustard powder, cayenne powder, and liquid smoke.
Lay the brisket on a large piece of foil.
Dry the brisket with paper towel and rub the seasoning over the entire brisket.
Wrap the brisket in the foil tightly and refrigerate for at least 8 hours.
Remove the brisket from the refrigerator and allow to rest at room temperature for 30 minutes before roasting.
Remove the brisket from the foil and place on the rack. Fill the bottom of the roasting pan with 1 inch of water.
Preheat the oven to 275℉. Insert a probe thermometer into the thickest part of the brisket.
Roast in the oven until the internal temperature is 165℉ (for 3-4 hour).
Wrap the brisket with foil and continue roasting until the internal temperature reaches 200℉.
Remove the brisket from the oven, leaving the foil on and place in a cooler to rest for 2 hours.
After the rest, slice 1/2 inch slices against the grain.