Preheat the oven at 350F or 180C.
In a bowl, whisk the butter and sweetener until pale in color.
Add the egg, mint or vanilla extract and whisk to combine.
Add the ground white sesame seeds, baking powder, salt, cocoa powder and mix with a spatula until a soft dough is formed.
Add the chocolate chips, nuts and mix until well combined.
Scoop the dough onto a baking tray lined with parchment paper. Flatten a bit as they will be crispier.
This recipe makes about 24 cookies at 20 g each. You can also make mini ones at 8 g each and it will yield about 70 cookies.
Top with unsweetened chocolate chips (optional)
Bake for 15 to 20 mins or until browned and crispy. For a softer texture, bake for a shorter time around 10 to 12 mins. Let the cookies cool for about 5 mins on the tray after baking then transfer to a wire rack to cool completely. The cookies will crisp up once cooled and they will be crispier the next day. If you find the cookies are not crispy enough, just pop back into the oven and bake for another few minutes until they are really browned and crispy. You may find that the oven is smoky hot but don't worry as they are not burnt but will be very crispy.
Store the cookies in an airtight container for 6 to 8 weeks. They can also be refrigerated and frozen. They tastes great straight out of the fridge and freezer.
You can also freeze the dough for later use. Just shape them into balls, chill in the fridge and once hardened, place into bags and freeze. When you want to bake them, let them defrost for a bit on the kitchen counter then bake accordingly.