Prepare the pork: Pat the pork shoulder dry with paper towels. In a small bowl, mix together the paprika, chili powder, mustard powder, garlic powder, salt, pepper, and cayenne to create a dry rub. Massage this spice mixture all over the pork shoulder, ensuring all sides are well coated.

Sear the meat: Heat vegetable oil in a large skillet over medium-high heat. Once hot, sear the pork shoulder on all sides until nicely browned, about 3-4 minutes per side. This step is crucial for developing deep flavor.

Prepare the slow cooker: Place diced onions at the bottom of your slow cooker.

Add liquids: In a bowl, whisk together chicken broth, barbecue sauce, apple cider vinegar, brown sugar, Worcestershire sauce, and minced garlic. Pour half of this mixture into the slow cooker.

Add the pork: Transfer the seared pork shoulder to the slow cooker, placing it on top of the onions. Pour the remaining sauce mixture over the meat.

Cook low and slow: Cover and cook on low for 8-10 hours or on high for 4-5 hours. The pork is done when it easily shreds with a fork.

Shred the meat: Once cooked, carefully transfer the pork to a large cutting board. Using two forks, shred the meat, removing any large pieces of fat.

Strain and reduce the sauce: Strain the cooking liquid from the slow cooker, discarding solids if desired. Transfer liquid to a saucepan and simmer over medium heat until reduced by half, about 10-15 minutes.

Combine and finish: Return the shredded pork to the slow cooker and add the reduced sauce to taste. Keep warm until ready to serve.

Serve: Toast hamburger buns if desired. Pile the pulled pork onto the buns, top with additional barbecue sauce, coleslaw, and pickles if using.