Spray the slow cooker with non-stick cooking spray and line the bottom with parchment paper. (you can forgo the parchment, but be sure to spray the slow cooker well).
In a medium sized bowl, whisk together the flour, baking soda, salt and cinnamon. Set aside.
In a large bowl, cream together the butter and brown sugar using an electric handheld mixer. Put the bananas onto a dinner plate and mash with a fork or potato masher until a uniform paste forms. Add the bananas into the batter and mix again until smooth. Mix in 1 egg at a time and add the vanilla extract.
Add the dry ingredients to wet ingredients and pour in the buttermilk, stir together using a wooden spoon or rubber spatula.
Pour the batter into the slow cooker and spread evenly.
Cook on HIGH For 2 hours. You may need to cook a little longer or less, depending on how hot your crockpot cooks.
Allow to cool completely before removing from the slow cooker and slicing. Enjoy!
Video
Notes
You want to use an oval slow cooker for this recipe for the center may not set with a larger slow cooker.
The banana bread can be stored at room temperature for up to 4 days in a zip top bag or airtight container