The chicken and sauce can be made up to two days ahead and stored in the refrigerator.

Chicken:
2 tablespoons dark brown sugar
1 teaspoon paprika
3/4 teaspoon ground cumin
1/2 teaspoon ground chipotle chile pepper
1/4 teaspoon ground ginger
1/8 teaspoon salt
2 pounds skinless, boneless chicken thighs
Cooking spray

Sauce:
2 teaspoons canola oil
1/2 cup finely chopped onion
1 tablespoon dark brown sugar
1 teaspoon chili powder
1/2 teaspoon garlic powder
1/2 teaspoon dry mustard
1/4 teaspoon ground allspice
1/8 teaspoon ground red pepper
1 cup ketchup
2 tablespoons cider vinegar

Remaining ingredients:
8 (1 1/2-ounce) hamburger buns, toasted
16 hamburger dill chips

2 tablespoons dark brown sugar 1 teaspoon paprika 3/4 teaspoon ground cumin 1/2 teaspoon ground chipotle chile pepper 1/4 teaspoon ground ginger 1/8 teaspoon salt 2 pounds skinless, boneless chicken thighs 2 teaspoons canola oil 1/2 cup finely chopped onion 1 tablespoon dark brown sugar 1 teaspoon chili powder 1/2 teaspoon garlic powder 1/2 teaspoon dry mustard 1/4 teaspoon ground allspice 1/8 teaspoon ground red pepper 1 cup ketchup 2 tablespoons cider vinegar 8 (1 1/2-ounce) hamburger buns, toasted 16 hamburger dill chips

1. Preheat grill to medium-high heat.

2. To prepare chicken, combine first 6 ingredients; rub evenly over chicken. Place chicken on a grill rack coated with cooking spray; cover and grill 15 minutes or until a thermometer registers 180°, turning occasionally. Let stand for 5 minutes. Shred with 2 forks.

3. To prepare sauce, while chicken grills, heat canola oil in a medium saucepan over medium heat. Add onion; cook for 5 minutes or until tender, stirring occasionally. Stir in 1 tablespoon sugar and next 5 ingredients (through ground red pepper); cook 30 seconds. Stir in ketchup and vinegar; bring to a boil. Reduce heat, and simmer 10 minutes or until slightly thickened, stirring occasionally. Stir in chicken; cook 2 minutes.

4. Place 1/3 cup chicken mixture on bottom half of each bun; top each with 2 pickle chips and top of bun.