In a medium bowl, whisk together the honey, Dijon mustard, soy sauce, apple cider vinegar, garlic powder, onion powder, black pepper, salt, and paprika until well combined.
Place the chicken thighs in the slow cooker and pour the honey mustard mixture over them, ensuring they are well coated.
Cover the slow cooker and cook on low for 6 to 7 hours or on high for 3 to 4 hours, until the chicken is tender and cooked through.
Once cooked, carefully remove the chicken thighs from the slow cooker and place them on a serving platter.
Optional: If you prefer crispy skin, place the chicken thighs under the broiler for 3-5 minutes until the skin is golden and crispy.
Drizzle some of the remaining sauce from the slow cooker over the chicken and garnish with chopped parsley before serving.