1. In the bowl of a stand mixer with the paddle attachment, combine brown sugar, sugar, and butter. Beat on medium until fluffy, about 3-4 minutes. 

2. Add in miso and tahini and mix until incorporated. 

3. Add egg and vanilla extract, mix, then scrape down the sides of the bowl and mix again to ensure everything is fully incorporated. 

4. In a separate bowl, whisk together flour, baking powder, and baking soda. 

5. Gradually add the dry ingredients to the wet mixture, pulsing a few times to avoid flour flying everywhere, then mix until a dough forms. 

6. Fold in 1/4 cup sesame seeds and mix until evenly distributed. 

7. Cover and refrigerate dough for at least 2 hours, or overnight for best results. If you’re short on time, refrigerate for at least 20 minutes. 

8. Preheat oven to 350ºF (180ºC). 

9. Place 1/4 cup sesame seeds in a shallow bowl. Scoop heaping tablespoons of dough, roll into balls, and coat them in sesame seeds. 

10. Place cookies on a greased baking sheet, spaced 2 inches apart. 

11. Bake for 10 minutes, remove from the oven, and bang the baking sheet on the counter to create a crumbly texture. 

12. Bake for an additional 4 minutes, or until cookies are golden and toasty. 

13. Let cool before serving and enjoy!