Preheat the oven to 325 degrees F. Pat the pork shoulder completely dry with paper towels.
In a bowl, combine the brown sugar, paprika, garlic powder, salt, pepper, chili and onion powders. Stir well to mix. Take about half of the mixture and rub it on the outside of the pork.
Heat a large dutch oven over high heat and add the canola oil. Add the pork and sear on all sides, about 1 to 2 minutes per side, until golden brown. Turn off the heat. Pour the beer (or liquid of choice) into the dutch oven and place the pot, uncovered in the preheated oven. Roast for 6 to 8 hours, until the pork is falling apart and shreds easily with a fork. Shred the pork (you can discard any bones at this time) and add in half of the remaining spice mixture. Toss the pork with a cup or so of BBQ sauce, then place it back in the oven for 30 minutes.
Before serving, taste the pork and add the remaining seasoning and sauce if desired or needed. Serve!
You can definitely make this ahead of time and reheat it. You can also make it in the crockpot, as well as reheat it in the crockpot on the lowest/warm setting.