Combine the sauce ingredients in a medium saucepan. Bring to a gentle simmer over medium heat, stirring occasionally. Cook for 10-12 minutes, until slightly thickened. Reserve 1/2 cup of the sauce for serving.
1 1/2 cups ketchup, 1/4 cup apple cider vinegar, 1/4 cup packed light brown sugar, 2 tablespoons molasses, 1 tablespoon Worcestershire sauce, 1 tablespoon yellow mustard, 2 teaspoons smoked paprika, 1 teaspoon garlic powder, 1 teaspoon onion powder, 1/2 teaspoon fine sea salt, 1/4 teaspoon black pepper, 1/4 teaspoon cayenne pepper
Heat the extra virgin olive oil in a large skillet set over medium-high heat. Season the chicken thighs with the salt, smoked paprika, garlic powder, and pepper. Sear for 2-3 minutes per side (in batches if needed), until browned.
2 pounds boneless skinless chicken thighs, 1 tablespoon extra virgin olive oil, 1 teaspoon fine sea salt, 1 teaspoon smoked paprika, 1/2 teaspoon garlic powder, 1/2 teaspoon black pepper
Transfer the chicken to a slow cooker and pour in the remaining barbecue sauce. Cover and cook on low for 5-6 hours, until the chicken is very tender and shreds easily.
Transfer the chicken to a large bowl and shred with two forks. Return the shredded chicken to the slow cooker and toss with the sauce.
Lightly toast the buns if desired. Pile the barbecue chicken onto the buns, drizzle with the reserved barbecue sauce, and top with coleslaw and pickles.