Ingredient Substitution Guide

1. Step 1

   Make the cookies: In a large bowl, with an electric mixer on medium speed, beat the butter, sugar and tahini until combined and fluffy, about 2 minutes. Add the egg yolks and vanilla and beat until combined. Reduce speed to low and beat in flour, baking powder and salt. Add the pistachios and sesame seeds and beat until evenly distributed. The dough should start to come together in small clumps. 

2. Step 2

   Divide the dough in half.  Tip each half out onto a sheet of plastic wrap—don’t worry, it will be crumbly. Knead and roll each portion of dough into a 2-inch-diameter cylinder, using wet hands and the plastic wrap to help shape the dough. Wrap cylinders in the plastic, roll to round off the edges and freeze until solid, 2 to 4 hours. (At this point you could wrap the dough well and freeze it for up to 3 months.) 

3. Step 3

   Heat the oven to 350 degrees. Using a sharp knife, cut ¼-inch slices from one frozen dough cylinder, rotating it between slices to keep the round shape. If the dough breaks apart simply press it back together. Place the slices 1-inch apart on parchment-lined baking sheets and bake until set and light golden around the edges, about 18 minutes. Transfer to a rack and let cool completely. The cookies will be fragile until they are cool. Repeat with the remaining dough.

4. Step 4

   Dip the cookies: Line two baking sheets with parchment paper. For the easiest and most effective dipping, melt the chocolate in the microwave in a short glass or ramekin that is wide enough to dip the cookies into but narrow enough that you have at least 1½ inches of chocolate at the bottom. Microwave the chocolate in 20-second intervals, stirring in between each, until smooth.

5. Step 5

   Dip the cooled cookies halfway into the melted chocolate, then dip in sesame seeds and transfer to the prepared baking sheets. Let set at room temperature or in the fridge. Store cookies in an airtight container at room temperature for up to a week or in the freezer for up to 3 months.

Tip

• Make sure to use chopped chocolate here, not chocolate chips, which will coat the cookies too thickly.