Pat the country style pork ribs dry with paper towels. In a small bowl, combine smoked paprika, garlic powder, onion powder, salt, black pepper, and cayenne pepper (if using) to create the dry rub. Sprinkle the rub generously over all sides of the ribs, pressing it in gently to adhere.

Heat olive oil in a large skillet or Dutch oven over medium-high heat. Once hot, sear the seasoned ribs in batches for 2-3 minutes per side until nicely browned. This step is optional but adds significant depth of flavor. Remove seared ribs and set aside.

In a medium bowl, whisk together ketchup, apple cider vinegar, brown sugar, Worcestershire sauce, Dijon mustard, liquid smoke (if using), and water (or beef broth) until well combined. Taste and adjust seasonings as desired.

Pour about half of the BBQ sauce into the bottom of your slow cooker. Arrange the seared ribs (or unseared, if skipping that step) in a single layer if possible, or stack them without overcrowding. Pour the remaining BBQ sauce over the ribs, ensuring they are well coated.

Cover the slow cooker and cook on low for 6-8 hours or on high for 4-5 hours, or until the ribs are incredibly tender and easily pull apart with a fork.

Carefully remove the cooked ribs from the slow cooker. If desired, you can shred the meat or serve the pieces whole. Spoon additional sauce from the crockpot over the ribs before serving.