Preheat your oven to 350 degrees F, grease or line a 9x5 loaf pan, set aside.
In the bowl of a hand or stand mixer fitted with a paddle attachment cream together the softened butter and sugar until light and fluffy, 3-4 minutes. Mix in the peanut butter and tahini. Add in the eggs one at a time, and the vanilla. Mix to combine. Add in the mashed bananas and gently mix to incorporate.
In a separate mixing bowl combine the flour, salt, and baking soda, mix to combine. Slowly add the dry ingredients into the wet and mix until incorporated, careful not to overmix. Pour the batter into the greased loaf pan and bake at 350 for 50-55 minutes, or until a toothpick inserted in the middle comes out clean. Allow to cool slightly before slicing.