Preheat your oven to 375°F (190°C).

In a mixing bowl, combine hoisin sauce, soy sauce, honey, oyster sauce, rice vinegar, minced garlic, Chinese five-spice powder, and sesame oil. Whisk until well blended.

Place chicken thighs in a resealable bag. Add half of the marinade, ensuring the chicken is well coated. Seal the bag and refrigerate for at least 2 hours, or overnight.

Before cooking, let the marinated chicken sit at room temperature for about 30 minutes.

Line a baking sheet with aluminum foil and arrange the chicken thighs skin-side up. Bake for 25 to 30 minutes or until fully cooked.

While the chicken bakes, pour the reserved marinade into a saucepan, heat until boiling, then reduce to a simmer for 10 minutes to thicken.

Carefully brush the chicken with the thickened marinade and broil for 2-3 minutes.

Remove from the oven and let the chicken rest for a few minutes before slicing and serving.