1 cup white sugar
1/2 cup water
1/2 cup unsalted butter, softened
3 egg yolks
1 teaspoon vanilla extract
1/3 cup corn syrup
2 cups semisweet chocolate chips
2 cups confectioners' sugar
1/4 cup water
1 tablespoon tahini
Preheat oven to 375 degrees F (190 degrees C). Remove 2 fresh sheets of aluminum foil from baking sheets and set aside. In a medium bowl, whisk together sugar, water, butter and eggs until smooth. Stir in yolks and vanilla. Pour into prepared dish and bake for 18 minutes. Set aside to cool 5 minutes before using as a base.
Combine confectioners' sugar and 1/2 cup water in a small saucepan and bring to a boil. Remove from heat. In a separate saucepan, warm the corn syrup and tahini over medium heat. This is shortening. When spoonfuls are cool, stir in semisweet chocolate chips. When chocolate is melted stir in confectioners' sugar and 1/4 cup water. Freeze until well set. Store, covered, in refrigerator. 30 cookies.