Peel papaya, halve lengthwise, and scoop out seeds. Cut each half into 4 lengthwise slices.
Spray a large, nonstick skillet with butter-flavored spray and put over medium heat.
Add papaya and sauté until lightly browned all over, about 7 minutes.
Sprinkle with brown sugar. Add rum and lime juice and swirl pan.
Turn papaya quarters to coat evenly. Divide between 2 plates.
Sprinkle with nuts. Buon Appetito!