Preheat oven to 350 degrees. Grease and flour a 9x5 loaf pan and set aside. Dice 1 cup strawberries, and slice 1 extra strawberry for the top.
In a large bowl combine the whole wheat flour, baking soda, salt, and cinnamon. Whisk together and set aside.
In another mixing bowl mash the bananas, add the Greek yogurt, egg, egg whites, melted butter, applesauce, honey and vanilla. Whisk together until completely combined.
Add the wet ingredients to the dry ingredients and fold together until just combined. Gently fold in the diced strawberries.
Pour the batter into the prepared loaf pan, top with strawberry slices and bake for 45-55 minutes or until a toothpick comes out clean.
Let the loaf cool in the pan for 5 minutes and then transfer it to a wire cooling rack to finish cooling.