Prepare the brisket a day before you would like to eat it. Place your brisket on a baking sheet lined with enough foil to cover the brisket. Mix the garam masala, garlic powder, onion powder, and salt. Massage the spice mix with your hands onto the brisket.
Mix the worcestershire and liquid smoke. Pour onto the brisket. Turn the brisket to make sure the liquid goes to the other side as well. Cover tightly with foil and marinate overnight in the refrigerator.
The brisket takes about six hours to cook, so start baking according to when you would like to eat it. Allow it 30 minutes to come to room temperature before you start baking. Heat the oven to 230° F. Add the brisket and cook for about 5 hours. After 5 hours, take the brisket out, pour the BBQ sauce over it and cook uncovered for an additional hour.