Marinate the Wings: In a large bowl, whisk together the soy sauce, pineapple juice, brown sugar, rice vinegar, ginger, garlic, sesame oil, and red pepper flakes (if using). Add the chicken wings and toss to coat thoroughly. Cover and refrigerate for at least 2 hours, or up to 4 hours. Avoid longer marinating times to prevent the bromelain in the pineapple juice from making the chicken mushy.

Prepare the Pineapple Teriyaki Sauce: In a blender or food processor, puree the pineapple chunks until smooth. In a medium saucepan, combine the pureed pineapple, soy sauce, honey, rice vinegar, ginger, garlic, sesame oil, and black pepper. In a small bowl, whisk together the cornstarch and water to form a slurry.

Cook the Sauce: Bring the pineapple mixture to a simmer over medium heat. Add the cornstarch slurry and whisk constantly until the sauce thickens, about 1-2 minutes. Remove from heat and set aside.

Preheat and Prep: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or aluminum foil.

Bake the Wings: Arrange the marinated chicken wings in a single layer on the prepared baking sheet. Bake for 20 minutes.

Flip and Baste: Flip the wings and bake for another 15 minutes. Increase the oven temperature to 425°F (220°C) and bake for a final 5-10 minutes, or until the wings are cooked through and the skin is crispy.

Glaze the Wings: Remove the wings from the oven and transfer them to a large bowl. Pour the pineapple teriyaki sauce over the wings and toss to coat evenly.

Broil (Optional): For extra-sticky and caramelized wings, arrange the sauced wings back on the baking sheet and broil for 1-2 minutes, watching carefully to prevent burning.

Garnish and Serve: Garnish the wings with sesame seeds and chopped green onions. Serve immediately with pineapple wedges, if desired.