01 -
Set your oven to 350°F and grease an 9x5 pan with oil or butter.
02 -
Smash the bananas in a big bowl using a fork or potato masher until smooth.
03 -
Mix in the butter first, then stir in sugar, eggs, and vanilla until smooth.
04 -
Gently work in flour, cinnamon, baking powder, salt, and baking soda until just blended.
05 -
Transfer the batter into your pan and bake for an hour, checking with a toothpick.
06 -
Cool in pan for a little bit, maybe 5-10 minutes, then move to a cooling rack.