Preheat the oven to 350. in a medium bowl, mash bananas. Add egg, greek yogurt, olive oil, TruEats sweetener, and vanilla. Mix until combined.
Add oat flour, baking soda, baking powder, cinnamon, and salt and mix until just combined.
Pour batter into a lined loaf tin. If you want, top batter with a banana sliced in half length wise. Bake for 48-53 minutes until toothpick comes out clean. Let it cool and enjoy!