Preheat the oven to 350 degrees and line a baking sheet with parchment paper.
Add 1 stick of butter to a small sauce pan on medium low heat. Cook until butter browns stirring often. Add the brown butter to a bowl and chill in the fridge for 5-10 minutes until it cools and slightly begins to harden. If you let it harden too much, microwave it about 10 minutes to soften.
Add brown butter and additional stick of softened butter to the mixing bowl.
Add in sugar. Mix until the texture is creamy.
Add in eggs while mixing on low.
Add in tahini. Mix again.
Add in brown sugar and vanilla. Mix until completely combined.
In a separate bowl, mix flour, baking soda, baking powder and kosher salt.
While mixing on low, slowly add the dry ingredients to the wet ingredients.
Fold in the chocolate chips.
Scoop about 2 tablespoon of the dough onto the baking sheet.
Bake 13-15 minutes.
Remove cookies from the baking sheet immediately to a cool rack. Allow to cool at least 5 minutes before serving.
Notes
Save extras in a ziploc or air tight container for up to 2 weeks on the counter.