Season chicken thighs on both sides with salt and pepper.
Mix peanut butter powder and water together in a large bowl until fully incorporated. Stir in hot honey, soy sauce, and garlic powder; mix until well combined. Add chicken thighs and turn in marinade, making sure both sides are well coated. Cover bowl and refrigerate 8 hours to overnight.
Preheat the oven to 375 degrees F (190 degrees C).
Transfer chicken thighs to an oven-proof dish.
Bake in the preheated oven until chicken is no longer pink at the bone and the juices run clear, 35 to 45 minutes. An instant-read thermometer inserted near the bone should read 165 degrees F (74 degrees C).
