In a mixer, beat the butter and the sugar for 4-5 minutes until fluffy and creamy
Lower the speed and add vanilla, cinnamon, salt, orange zest and tahini. Beat to a smooth consistency. Add the flour and baking powder and process to a smooth and malleable dough. falling apart, that's fine. If the dough is too crumbly, add a bit more tahini
Preheat the oven to 350 F
Mix the confectioners' sugar with cinnamon in a small bowl
Pinch small pieces off the dough and roll balls the size of large olives. Roll the balls in the sugar-cinnamon mixture
Arrange the cookies on a tray lined with baking paper, spacing them. Bake for 15 minutes. The cookies should remain rather light in colored. During baking, there might be some "smoke" due to the cinnamon (at least with my oven), but don't panic! Don't touch the cookies until they cool completely or they will crumble. Store in an airtight jar