In a large bowl, mix together the chicken, ginger, vegetable oil, sesame oil, pineapple juice and soy sauce until everything is fully combined. Then set aside as you prepare the marinade.
To make the jerk marinade: Put the cornstarch with two teaspoons of water in a small bowl and stir until it forms a paste. Then add the brown sugar, garlic and green onions to the marinade, stirring until it's thoroughly blended.
Pour the jerk marinade over the chicken mixture and mix with care until everything is perfectly integrated. Cover bowl with plastic wrap and let it sit in the refrigerator for a minimum of 30 minutes or up to overnight.
Preheat oven to 375°F. Peel and core the pineapple, collecting any juices that are released during the process. Cut up the pineapple into 8 wedges and place them in an oven safe dish with all of the collected juices.
Place chicken mixture onto a parchment paper-lined baking sheet, spreading it out evenly with a spatula or spoon. Bake inside preheated oven for 25-30 minutes, or until the chicken is fully cooked through and looks golden brown.
Serve the spicy jerk chicken with succulent pineapple wedges in a bowl over cooked rice and garnish it with freshly cut green onions and sesame seeds if desired.