Drain pineapple chunks, reserving 1/4 cup juice. Set drained pineapple and juice aside.
Melt margarine in a large nonstick skillet over medium heat; add pineapple chunks, reserved juice, brown sugar, rum, and cinnamon. Bring to a boil; reduce heat, and simmer 5 minutes, stirring frequently. Serve warm.
Light and Luscious