In a mixing bowl, cream together the butter, tahini, granulated sugar, and brown sugar until the mixture is smooth and emulsified (no chunks of butter!) Scrape down the sides of the bowl to ensure everything is well combined.

Gradually add the egg, egg yolk, and vanilla extract to the creamed mixture. Continue to mix until the mixture is fully homogeneous, scraping the bowl as needed.

On low speed, add the all-purpose flour, baking soda, and kosher salt. Mix until just combined, being careful not to overmix.

Gently fold in the chocolate chunks and halva cubes by hand or on a low mixer speed until evenly distributed throughout the dough.

Transfer the dough to some plastic wrap and chill in the refrigerator thoroughly before scooping.

Scoop out portions of dough. Amanda likes to use a flat yellow scoop or green scoop. Place two layers of dough balls on a tray, separated by double parchment paper. You can freeze the portioned dough until ready to bake.

Preheat the oven to 325°F.

Just before baking, flatten each cookie slightly. Press one side of each cookie in white sesame seeds and sprinkle with flaky sea salt on the other side.

Bake for about 13 minutes, or until edges are golden and centers are set. Adjust baking time as needed, depending on your oven. Half way through, flip the cookie sheet around for even baking.