Spray or spread butter in a bread loaf pan
I use my stand mixer with balloon attachment to mash the banana, that way you just keep adding to it.
Add mashed banana, butter and eggs to the bowl, mix.
Add sugar, milk, vanilla and sourdough discard, mix.
Into your wheat grinding bowl (or a separate bowl add pre-ground flour), add baking soda, cinnamon and salt, and mix.
Add dry ingredients to the wet ingredients. Mix to combine, no more.
Fold in chocolate chips (or other mix ins)
Cover the bowl and put it in the fridge for 24-48 hours OR let stand 15 minutes and then proceed to baking.