Sift the flour, baking powder, and salt together in the bowl of a stand up mixer. Add in the almond flour and sugar. Mix on low speed to combine, and then add the butter, tahini paste, honey, and vanilla. Mix on medium low speed until the mixture is pebbly with no butter pieces larger than a small pea, about 2 to 3 minutes. Add the rum now, if using. Continue to mix the dough until it is just combined.

Pour the sesame seeds into a small bowl and set aside.

Line 2 baking sheets with parchment paper. Adjust one oven rack to the upper-middle position and another to the lower-middle position, and preheat oven to 325 degrees F.

Using your hands, roll the dough into balls about the size of a large marble (you should get roughly 40 cookies that size). Dip one side of a ball into the sesame seeds, place it sesame-side up on a parchment lined sheet, and press gently with your finger to flatten it slightly. Repeat with remaining balls.

Bake the cookies, turning the sheets and rotating them between top and bottom racks midway through, until the are firm to the touch and only slightly golden, about 8 minutes. Do not overbake them.

Let them cool completely on the pans before transferring them to a rack.