Gather all the ingredients.
In a large bowl, combine the flour and baking soda.
In a separate bowl, mash the bananas.
Add the eggs, granulated sugar, brown sugar, vanilla extract, and Greek yogurt into the mashed banana mixture. Whisk until smooth.
Add the chopped apples and walnuts into the mashed bananas.
Mix the dry ingredients into the wet ingredients. Stir it just until well-combined, being extra careful not to over mix it.
Spray at 9in.x13in. baking sheet with cooking oil. Spread the batter over it evenly.
Bake the banana apple bread at 350°F for about 30 minutes or until a toothpick comes out clean. Let it cool to room temperature, slice, and enjoy!