Heat a large nonstick skillet over medium-high heat.
Add oil to pan; swirl to coat.
Add pork to pan; cook 3 minutes on each side or until browned.
Transfer pork to a 5-quart electric slow cooker coated with cooking spray, reserving drippings in pan. Reduce heat to medium.
Add onion to drippings in pan; saut 3 minutes or until tender. Stir in 2 cups water, scraping pan to loosen browned bits. Stir in brown sugar and next 3 ingredients (through ginger).
Remove pan from heat.
Add apples to slow cooker; pour onion mixture over apples. Cover and cook on LOW for 3 to 3 1/2 hours or until tender.