Preheat your grill to medium heat (about 375°F to 400°F) or preheat your oven to 400°F if cooking indoors. Lightly oil the grill grates or line a baking sheet with parchment paper.

In a small bowl, mix the smoked paprika, garlic powder, kosher salt, and black pepper. Pat the chicken thighs dry with paper towels, rub them with olive oil, and coat evenly with the spice mixture.

In a small saucepan, combine the ketchup, chopped chipotle peppers, brown sugar, apple cider vinegar, and Worcestershire sauce. Bring to a gentle simmer over medium-low heat, stirring occasionally.

Let the BBQ sauce simmer for 5 to 7 minutes until slightly thickened and fragrant. Remove from heat and divide the sauce into two bowls: one for basting raw chicken and one for serving.

Place the seasoned chicken on the grill (skin-side down first) or on the prepared baking sheet. Cook for 15-20 minutes, turning halfway, until the chicken develops a nice char and the skin becomes crispy.

Brush the chicken generously with the basting BBQ sauce during the last 10 minutes of cooking. Continue to cook, turning and basting frequently, until the internal temperature reaches 165°F and the sauce is sticky and caramelized.

Remove the chicken from the heat and let it rest for 5 minutes to lock in the juices. Serve warm with the reserved clean chipotle BBQ sauce on the side and your favorite summer side dishes.