Combine kecap manis, soy sauce, garlic, oil, vinegar, cumin and coriander in a small bowl. Reserve 2 tablespoons of the marinade in a medium bowl. Place chicken in a large sealable plastic bag. Pour the remaining marinade into the bag. Marinate in the refrigerator for at least 2 hours or overnight.
Add peanut butter, water, ketchup and hot sauce to taste to the reserved marinade and whisk to combine. Refrigerate until ready to use.
Position rack in upper third of oven; preheat broiler. Line a broiler pan or baking sheet with foil and coat with cooking spray.
Remove the chicken from the marinade and thread equal amounts onto six 12-inch skewers. (If using wooden skewers, cover the exposed end of each skewer with foil to prevent burning.) Broil the skewers until the chicken is cooked through and no longer pink in the middle, 6 to 8 minutes per side. Serve the sates with the reserved peanut sauce for dipping.