In a large bowl, whisk together the soy sauce, honey, brown sugar, rice vinegar, oyster sauce, hoisin sauce, sesame oil, garlic, ginger, and Chinese five-spice powder until well combined.
Add the chicken wings to the bowl and toss until they are evenly coated in the marinade.
Cover the bowl with plastic wrap and refrigerate for at least 1 hour, or preferably overnight, to allow the flavors to fully develop.
Preheat your oven to 400°F. Line two baking sheets with foil or parchment paper and place wire racks on top for easy cleanup.
Arrange the wings in a single layer on the wire racks, reserving the marinade for later.
Bake the wings for 35-40 minutes, turning halfway through, until they are golden brown and slightly charred on the edges.
While the wings bake, pour the reserved marinade into a large saucepan. Add 1/2 cup of water and bring the mixture to a boil over medium heat. Make sure it is a strong boil as this is important.
Reduce the heat and let it simmer for 5-7 minutes, allowing the sauce to reduce slightly.
Stir in the cornstarch slurry and continue simmering for another 2-3 minutes until the sauce thickens and becomes sticky.
Remove the baked wings from the oven and transfer them to a large mixing bowl.
Pour the thickened sauce over the wings and toss until they are evenly coated.
Place the sticky wings on a serving platter, garnishing with toasted sesame seeds and sliced scallion for a fresh finish.