1. Preheat the oven to 350°F (180°C). Line two baking sheets with baking parchment and set aside. Chop the chocolate coarsely and set aside.

2. Add the butter, tahini, brown sugar, and vanilla extract to the bowl of your kitchen machine and mix on high for 3-4 minutes until everything looks pale and fluffy. Add the egg and mix in on low until incorporated completely. Mix the flour with baking powder, and salt. Add to the bowl and mix until just combined. Add the chopped chocolate and fold in. Use a cookie scoop* and place about four dough portions with enough space in between on each baking sheet. Sprinkle with sesame seeds and bake the first baking sheet for 15-16 minutes. If you want the cookies flat, take the baking sheet out after about 6 minutes and let it drop on your work surface to deflate the cookies a bit – place back in the oven and continue baking. The cookies are done when the edges got a bit of color but the centers are still a bit soft. Take out of the oven and let the cookies cool down on a wire rack. Repeat with the second batch.