Preheat oven to 350 degrees F. Line 9 x 5 loaf pan with unbleached parchment paper. Set aside.
In a large bowl, mash bananas with a fork. Add eggs, Greek yogurt, maple syrup, oil, vanilla, cinnamon, baking powder, baking soda and salt. Whisk to combine.
Add flour and stir gently just enough to mix. Then add walnuts and give a few more stirs to incorporate.
Pour batter in prepared loaf pan, garnish with banana slices (pressing on them) and bake for 60-70 minutes or until a toothpick inserted in the middle comes out clean.
Remove from the oven and let cool for 15 minutes. Then transfer to a cooling rack to cool off more. Cut into 10 slices and enjoy!
Notes
Store: Keep in a cool dry place in a glass airtight container for up to 4 days.
Freeze: Wrap tightly and store in freezer safe container up to 3 months.