Position the oven rack in the center and preheat the oven to 350°F. Lightly grease a standard 8x4 inch loaf pan with nonstick spray and set aside.
In a large bowl, mash the bananas with a fork until almost smooth, but a few lumps are okay. Add the egg and egg yolk and whisk until combined then whisk in the coconut oil and greek yogurt.
Once combined, whisk in the brown sugar, honey and vanilla. Add the baking soda, baking powder, and salt and using a wooden spoon or rubber spatula, stir until combined. Slowly stir in the flour, stirring gently between each addition, being careful not to over mix. Add the dark chocolate chips if using them and fold until just combined.
Pour the batter into the prepared bread pan and bake for 55-60 minutes until a toothpick inserted in the center comes out clean. Check the bread at around the 40 minute bark for browning. The the bread is browning too much around the edged cover with foil and place back in the oven to finish baking.
Remove from the oven and allow to cool on a wire rack for about 20 minutes then remove from pan and allow to cool completely before cutting.
Bread is stored well in an air tight container in the refrigerator for up to 5 days or in the freezer for up to 2 months.
If you don't have coconut oil, you can substitute with melted butter or vegetable oil.