In stand mixer fitted with a paddle attachment, add in your sugars, orange zest and butter. Beat until smooth and creamy, about 2 minutes. Note, if you don't have a stand mixer, this can be done by hand with a whisk and some elbow grease.

Add the egg, tahini, vanilla, and orange juice. Mix until incorporated.

Slowly add in the dry ingredients, mixing gently until it's fully mixed in and there are no dry pockets (use a rubber spatula to scrape down the sides of the bowl. Don't overmix.

Remove the bowl from the mixer and fold in the chocolate chunks by hand with the rubber spatula. Then cover and chill the dough for at least 30 minutes (up to 2 hours).

Preheat the oven to 350° F. Using an ice cream scooper, or a 1/4-cup measure, form the dough into balls and place them onto a sheet pan lined with parchment paper. I like to flatten mine somewhat, for a less domed cookie. Allow some space in between each cookie for spreading.

Top them with flaky salt and bake for 12-15 minutes, until the edges are lightly brown and the center is almost set. Cool on the pan for 5 minutes before moving them to a cooling rack.