Crock Pot BBQ Chicken

3 large chicken breasts (can be frozen)

1 bottle of your favorite barbecue sauce

1/4 cup brown sugar

1/4 cup apple cider vinegar

1 teaspoon garlic powder

1/2 teaspoon cardamom

1 tablespoon grainy mustard

Place chicken breasts in crock pot. Mix together the sauce ingredients. Pour over chicken. Cook on low 4 to 6 hours, checking occasionally for doneness. Remove chicken and shred. If sauce is too thick add a little water or chicken broth to it. Return chicken to sauce. Spoon onto warmed hamburger buns and serve