Turn crockpot on high. brush bottom & sides of crockpot with butter & line with foil( this will help remove it when its done), brush the foil with butter as well
slice butter into pats & place in the bottom of foil liner, sprinkle brown sugar over & then place bananas cut side down.
Mix cake mix according to pkg directions & add the ginger, cinnamon & nutmeg. pour over bananas.
Place a dbl length of dry paper towels (**)over the TOP of crockpot rim & a sheet of foil to seal it in , place lid on tight & cook for 2- 2 1/2 hrs...check after 2...the sides should be brown & when you touch the center of the cake it should spring back.
turn crockpot off & using the foil remove the cake & set aside to cool for 30 min. after cooling take a plate & place over the cake & invert it , remove foil
serve & enjoy
** since a crockpot cooks with moist heat the paper towels will help absorb excess moisture & keep it from making the top of the cake soggy