1 stick [115g] unsalted butter, at room temperature
1/2 cup [100g] granulated sugar
1/2 cup [100g] brown sugar
1/2 tsp [3g] salt
1 large egg [50g]
1/2 cup [125g] tahini
1 Tbsp [15g] milk
1 tsp [5g] vanilla
2/3 cup [90g] sesame seeds
Combine the flour and baking soda in a medium mixing bowl. Whisk together until evenly blended and lump-free. Stir the chocolate chips into the dry ingredients.
Place the butter, sugar, brown sugar, and salt in the bowl of a stand mixer fitted with the paddle attachment. Beat at medium-high speed for about 2 minutes, until a little lighter and fluffier. Scrape down the sides, and add the egg, tahini, milk, and vanilla. Beat at medium-high speed until silky-smooth and lighter in color (about 1 minute).
Add the dry ingredients to the wet ingredients, and mix at low speed just until it all comes together. Stop mixing once it’s combined.
Cover and rest the dough in the refrigerator for at least 30 minutes, up to 48 hours.*
Once you’re ready to bake, preheat the oven to 375°F [190°C] and line some sheet pans with parchment paper.
Shape the dough into scant-1/4-cup blobs [50g]. Roll one between your hands until smooth, then roll in the sesame seeds, and then place on a prepared sheet pan. Gently press the dough ball’s top down slightly so it’s just a little flattened. Repeat with the remaining ones, leaving space between each cookie (they will spread).
Bake for about 15 minutes, until the edges of the cookies are set, but the centers aren’t completely set. Slide the parchment off the pan and let the cookies cool right on the parchment.
* The longer you let it rest, the better the cookies’ texture will be. This step isn’t really about chilling the dough, as it can be baked the moment you finish mixing it. See the note above the recipe for more info on resting.