- Preheat oven to 350°. Chop nuts, set aside. 
- Melt butter in 12” oven-proof skillet. Remove from heat, stir in brown sugar and stir until well blended. 
- Drain pineapple reserving juice, set aside. 
- Arrange pineapple slices over sugar mixture. Place a cherry half in center of each slice. Sprinkle with nuts. 
- Add enough water to pineapple juice to make 1 1/3 cups liquid. 
- In bowl combine cake mix, liquid, eggs and oil; whisk until well blended and smooth. 
- Pour over pineapple in skillet. Bake 35-40 minutes. 
- Remove from oven Cool 5 minutes, loosen edges of cake and invert onto large serving plate. Cool slightly. Top with cool whip and serve.