Slow-Cooked Pulled Pork Sandwiches

1 boneless pork shoulder, cut into 2-inch chunks
1 cup chopped onion
2 14 oz. bottles of BBQ sauce
1/2 cup brown sugar
3 tbsp. Worcestershire sauce
5 tbsp. chili powder
4 tbsp. garlic powder
2 tbsp. salt
2 tbsp. pepper
1 medium-sized, heat-resistant jar or plastic container
Place pork into your slow cooker and preheat to low or high, whatever your preference (see cooking times below).
In a large bowl, combine chopped onion, BBQ sauce, brown sugar, Worcestershire sauce, and spices. Pour over pork and mix well, so that the pork is covered in the mixture. Cover and cook on low for 5-6 hours, or high for 3-4 hours. About every half hour, stir the pork with a large spoon.
Once done cooking, transfer the pork chunks with tongs or a slotted spoon to a large cutting board. Drain the sauce by ladling it into a heat-resistant container, leaving about 1 inch of sauce remaining. Place the container in the freezer to harden the sauce and enable easy disposal.
Pull apart the chunks of pork with two forks, until flaky. Transfer the pulled pork back into the pot and mix with the remaining BBQ sauce. Taste and add more spices, if desired.
Serve on hamburger buns, or separated and halved dinner rolls for bite-sized sliders.