Butter (or use cooking spray) the liner of the slow cooker.
Cut 2 pieces of parchment paper. Fold in thirds, length-wise. Place the paper one length wise and the one width wise in the slow cooker, like an X. Butter the top of the parchment as well.
In a large mixing bowl, mix the melted butter, granulated sugar, and light brown sugar with a hand mixer until all ingredients are combined.
Add the mashed bananas and ½ cup mini chocolate chips. Mix until combined.
Add the eggs, maple syrup, and vanilla extract. Mix wth a hand mixer.
Add the half flour, baking powder, baking soda, ground cinnamon, and ground ginger. Mix until ingredients are incorporated, then add the remaining flour and mix until you have no more dry flour.
Once all the ingredients are incorporated, pour them in the prepared liner of the slow cooker.
Cook on high for 2 hours 30 minutes or until the cake's internal temperature reaches 200F.
Take out of the slow cooker liner using the parchment paper.