Start by greasing a 6-quart slow cooker with nonstick cooking spray. This is a crucial step to ensure your bread comes out easily once it's done. Next, cut a long piece of parchment paper in half and lay it in the bottom of the slow cooker in a plus shape. This will serve as a base for the bread, making it easier to lift out once it’s cooked. Grease the parchment paper again with nonstick cooking spray and set it aside.
In a small bowl, combine the flour, baking soda, baking powder, cinnamon, and salt. Mix these dry ingredients well to ensure they are evenly distributed. This step is important because it prevents clumping and ensures consistent flavor and texture throughout your bread.
In a large mixing bowl, add the melted butter, white sugar, brown sugar, eggs, vanilla, and mashed bananas. Stir them together until well combined. You want a smooth mixture where the sugars are dissolved and incorporated.
Next, gradually add the dry ingredient mixture to the wet ingredients. Gently mix until just combined. Be careful not to overmix; it's okay if there are a few lumps. Overmixing can lead to dense bread, and we want it to be light and fluffy.
Now it's time to fold in the mini chocolate chips. If you love banana bread, feel free to get creative with other mix-ins here, like nuts or dried fruits. The chocolate chips will melt slightly in the slow cooker, adding delicious pockets of sweetness to every bite.
Pour the banana bread batter into the prepared slow cooker pan and spread it evenly in the bottom. Make sure it's level to ensure even cooking. Cover the crockpot and set it to low heat, cooking for about 3 to 4 hours. It's best to check it at the 3-hour mark; the bread should be set in the middle.
Once the bread is set, let it cool briefly. Carefully use the parchment paper to lift the bread out of the crockpot. Allow it to cool completely on a wire rack before slicing. This will help maintain its shape and texture.
Finally, slice the bread and serve it warm or at room temperature. Enjoy the fruits of your labor with a spread of butter or even a drizzle of honey, if desired.