Preheat your oven to 350°F (180°C). Lightly coat a 9-inch round cake pan with butter, then line the bottom with parchment paper for easy release.
In a small bowl, combine the tahini and orange juice.
Add the quartered dates and sliced bananas, stirring gently to coat.
In a separate large mixing bowl, cream together the butter and caster sugar until light and fluffy.
Gradually add the beaten eggs to the butter mixture, mixing well.
In another bowl, sift together the flour, baking powder, and salt.
Carefully incorporate the dry ingredients into the wet mixture, stirring gently until they are just combined.
Add the tahini-orange juice mixture with the dates and bananas, then fold in the toasted sesame seeds.
Transfer the batter into the prepared cake pan, then use a spatula to level the surface evenly.
Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool completely in the pan before transferring to a wire rack.