Spray a 9x5-inch loaf pan well with non-stick baking spray. Set aside for now.
Add all ingredients (starting with bananas in first and oats in last) into a large blender.
Blend on high speed for 30 to 60 seconds until blended well and no large chunks of banana remain in the batter.
Pour the batter evenly into the prepared loaf pan.
Place in oven and bake 40 to 45 minutes or until toothpick inserted in the middle comes out clean. This is a very moist bread so the toothpick will be a little wet but it will no longer have raw batter stuck to it.
Let bread cool completely before removing from loaf pan and slicing. If sliced too early, the bread will fall apart.
Notes
Don't blend the ingredients for too long. We still want some chewy oats in the batter; otherwise, the bread will be too dense.
Place tin foil over the loaf pan if the loaf browns too much before it's done baking.
To store: Store leftovers in an air-tight container at room temperature for up to 3 days or in the fridge for up to a week. Let the bread cool completely before placing it in a container for storage.
To freeze: Freeze individual slices tightly wrapped in plastic wrap for up to 3 months.
Mama says, “Make sure to always check your labels!”