Optionally, line a 6-quart to 7-quart slow cooker with a liner if using one.

Drizzle 1 tablespoon olive oil over the bottom of the liner or slow cooker.

To a large, gallon-sized ziptop plastic bag, add the chicken, cornstarch, salt, pepper, seal bag, and toss to coat chicken evenly. Add chicken to the slow cooker, evenly distributed; set aside.

To a 2-cup measuring cup or medium bowl, add the orange marmalade, soy sauce, rice wine vinegar, sesame oil, ginger, garlic, remaining 1 tablespoon olive oil and stir to combine.

Pour mixture over the chicken, using a spoon to distribute the sauce as necessary, making sure all pieces are coated.

Cook covered on high for about 2 hours or on low for about 4 hours. Start checking on high at 90 minutes and on low at 3 hours until chicken is done (reaches 165F).

Add chicken to a plate with as much extra cooking sauce spooned over the top as desired, garnish with sesame seeds, green onions, and optional orange wedges, and serve immediately.