Preheat oven to 350 degrees F. Spray a 9-inch square baking dish with cooking spray.
Process ½ cup black sesame seeds in a food processor until finely ground. Add ½ cup honey and process until the mixture becomes a paste.
Cream together ½ cup softened butter with ¾ cup brown sugar in the bowl of a stand mixer for 3-4 minutes or until fluffy. Add the eggs one at a time, beating well after each addition. Add 4 mashed bananas, ¼ cup yogurt, and 1 teaspoon vanilla, the black sesame paste, and mix until combined.
Add the dry ingredients including 2 cups of all-purpose flour, ½ teaspoon salt, 1 teaspoon baking powder, ¾ teaspoon baking soda, 3 tablespoon sesame seeds, and stir just until combined. Pour the batter into the prepared baking pan.
Cut the banana in half lengthwise and arrange it on top of the cake, gently pressing it in. Bake the black sesame banana bread for 45 minutes - 1 hour or until a toothpick inserted in the center comes out clean.