Browning the butter is technically optional but the extra time is SO worth it! The biggest problem I see people run into when using brown butter in cookies, is not letting the butter cool completely to room temperature before adding it to the dough. So I highly recommend browning the butter the night before you want to make these tahini chocolate chip cookies.
Using a stand mixer with a paddle attachment, or hand mixer, cream the room temperature brown butter, tahini, brown sugar, and granulated sugar until smooth and creamy.
Add in the eggs and vanilla extract and beat until light, fluffy, and pale in color. This should take 2-4 minutes which seems like a long time, but you'll see a huge difference in the texture afterwards.
Add in the flour, baking soda, and salt and mix until thoroughly combined. The dough should be wet and sticky and you might think you need more flour but you don't!
Gently fold the chocolate chips into the cookie dough.
Scoop a generous 3 tablespoons of dough and roll into balls. I use a size 20 cookie scoop. If desired, press some extra chocolate chips into the tops of the cookie dough balls.
Cover the dough balls and chill in the fridge overnight for best results. If you absolutely can't wait, just chill it for at least 2 hours.
Chilling the dough is super important so that the cookies don't spread!
To bake, place 2-3 inches apart on a parchment lined baking sheet.
Bake at 350°F on the center rack of the oven for 9-11 minutes or until the edges are set and the centers are still soft.
Remove from the oven and let rest on the baking sheet for 2-3 minutes, then transfer to a cooling rack.
To make brown butter, melt unsalted butter over medium heat, stirring frequently. Watch closely for the butter to develop brown specs and a nutty aroma. Once you start seeing brown specs, let cook for just a few seconds longer (watch very carefully or it will burn). Remove from the heat and pour into a small bowl so that it doesn't continue to cook. Set aside and let cool in the fridge or freezer for at least 20 minutes until it's soft and pliable (letting it sit overnight is best). Note: For every ½ cup (1 stick or 113g), you'll lose about 1 tablespoon (14g) to evaporation while cooking. So you can either add in an extra 1 tablespoon before browning, or if you're browning big batches, just make up the weight difference in your recipe with regular unsalted butter if needed.Store cookies in an airtight container at room temperature for up to a week.Freeze pre-rolled cookie dough balls in the freezer for up to 6 months.