Combine molasses, salt, and water a container that is at least 6 quarts in size. Add pork making sure it is completely submerged in brine, cover, and let sit in refrigerator for a minimum of 8 hours. 12 hours is ideal.*(Note: I have run out of molasses before and used a mixture of 1 part molasses and 1 part dark corn syrup and 1/2 part dark brown sugar.)*.
Rub: Combine all ingredients for rub mix in a small mixing bowl and stir to mix well. Feel free to adjust the amount of pepper if you want it spicier. You will have spice left over but do not worry. It makes a great rub for chicken, pork or beef, grilled or cooked inside.
Remove pork from brine and pat dry. Make some punctures in the meat with a sharp knife and rub the spice rub evenly all over the meat, patting to to make sure as much of the rub as possible adheres. More rub will adhere to the meat if you are wearing latex gloves during the application. I let it sit for about 10-15 minutes and add more rub until I have a really good coating all over the pork. Do not worry it will be too spicy. You have a large amount of meat to season. It cooks into the meat and some even drips off into the juices. All this makes a crust of sorts on the meat that is amazing and helps to seal in a lot of the juices.
Preheat smoker to 210 degrees F. Place pork in smoker and cook for 10 to 12 hours, maintaining a temperature of 210 degrees F.
After 10 hours of low smoking, insert a fork into the meat in a few places. If the meat falls apart easily when pulling with a fork it is done. If you do not want to smoke it that long or you have to go somewhere (like to bed! lol ) I have taken it off the heat after about 4 hours and placed it in a roaster. Cover the meat with foil and put in oven on the lowest setting and allow to cook until done. I sometimes do this before I go to bed if I do not feel like 'pulling' all the pork at that time.
Remove the meat to a large pot or roaster if you have not done so already in the previous step and allow it to cool for at least 1 hour or until the meat is cool enough to handle.
Sandwiches: Pull meat apart with 2 forks or with your hands (I wear latex gloves again) discarding fat if you desire. Serve on buns as a sandwich with your favorite BBQ sauce or top a baked potato with the BBQ sauced meat.
Roast: Slice against the grain as thin or thick as you like. Great served with any type of gravy. You may want to remove the roast a little before the falling apart stage for slices that are neater.
The juices that accumulate in the roaster make a wonderful gravy. I always remove the fat from the juices first bc pork can be very fatty.
Note: If you use the smoker/oven method you will have more accumulated juices as they will be saved in the roaster rather than fall in the fire.