Spray the insides of 2 large microwave-safe mugs with cooking spray.
Divide the crushed pineapple between the mugs.
Dive the brown sugar between each mug. Set the mugs aside.
Mix together cake mix, Reddi-wip, and egg in a medium bowl. Divide batter between the two mugs.
Individually, microwave each mug on HIGH for approximately 1 minute 15 seconds to 1 minute 30 seconds until set - being careful not to overcook or they will become spongy.
Remove from microwave and loosen around the edge with a butter knife. Then invert onto a plate. Do this for both mugs.
Top each cake with a cherry.
Serve while warm with additional Reddi-wip on the side, if desired.
Enjoy!
Notes
Store unused dry cake mix in baggie or sealed jar for fun desserts later!
Recipe by It's Free At Last at https://itsfreeatlast.com/pineapple-upside-down-mug-cakes-scrumptious-treat/