Preheat the oven to 350°F and position rack to the middle of the oven.
Cream butter, sugar and tahini until smooth and well integrated.

Next, beat in the eggs until combined. Add in the baking soda, cinnamon, salt and flour and mix until combined.

With a tablespoon, scoop out 1/4 of the dough and add in the cocoa powder in to it to make a well mix chocolate dough. Then make a flat sheet of 2 butter and 1 chocolate dough,and sandwiches the chocolate btw the 2 butter dough now cut into desired shapes and design with fork

Sprinkle the sesame seeds on top of the cookies.

Bake for 20 minutes, until the edges begin to brown. Cool for two minutes on cookie sheet and then move to a wire rack, letting them cool completely.