Preheat to 200°C and line a baking sheet with parchment paper.
Whisk pineapple juice, soy sauce, brown sugar, garlic, and ginger in a large bowl until sugar dissolves.
Add wings, toss to coat, cover, and chill for 30 minutes.
Arrange wings on the sheet, season with salt and pepper, and bake 25–30 minutes, flipping halfway. Broil 1–2 minutes if needed for crispiness.
Whisk cornstarch and water. Simmer leftover marinade with pineapple chunks, add slurry, and cook until thickened. Season to taste.
Toss baked wings with warm sauce and garnish if desired. Serve hot.