Preheat the oven to 350°F (175°C) and grease a 9x5 inch loaf pan or line it with parchment paper.
In a large mixing bowl, whisk together the mashed bananas, tahini, melted butter, sugar, egg, and vanilla extract until fully emulsified.
In a separate bowl, sift together the all-purpose flour, baking soda, and salt.
Gently fold the dry ingredients into the wet mixture using a spatula until just combined; do not overmix to avoid gluten development.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Sprinkle the surface evenly with toasted sesame seeds.
Bake for 50 to 60 minutes, or until a cake tester inserted into the center comes out clean.
Allow the bread to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.