Preheat the oven to 250 degrees F. Pour 3 cups water into the bottom of a large roasting pan with a rack and add the liquid smoke.
In a small bowl, mix the salt, brown sugar, and all remaining spices until well combined. Rub the spice blend over the entire surface of the brisket and lay the brisket on the wire roasting rack. Insert an oven-safe meat thermometer into the thickest part of the brisket and cover the roasting pan tightly with foil. *If you have an oven with a built-in meat thermometer, run the wire out the side of the pan. If you are using a standard meat thermometer, insert it into the brisket, through the foil, so you can see the reading.
Slow roast in the oven until the internal temperature reaches 155 degrees F. Then remove the foil and continue roasting until the internal temperature reaches 168 degrees F. Depending on your oven, and where you inserted the meat thermometer, this process may take 5-6 hours.
Take the brisket out of the oven and allow it to rest for 20 minutes before serving. Cover it loosely with foil to help retain the heat. Cut the brisket across the grain into thin slices, and serve warm.