In a food processor, pulse together the sugar and vanilla beans pieces till theyu2019re pulverised. Sieve the mixture to remove any seeds. (I didnu2019t sieve the mixture).
In a medium bowl, sift together the vanilla sugar, cornstarch and sea salt. Add the butter. With a pastry cutter, cut in the butter till the dough resembles coarse meal. Mix in the vanilla extract, egg and chocolate chips, combining thoroughly. Chill for 30 to 40 minutes.
Using a small scoop (I used a melon baller), shape the dough into 1/2" or 3/4u201d balls and drop onto parchment lined baking sheets, spacing them about 2 1/2" apart. These cookies are full of butter and will spread a lot!
Bake at 190C (375F) for 8 to 10 minutes, until the edges of the cookies are golden brown. Cool on cookie sheets for one minute, and then transfer the cookies with the parchment sheets to wire racks and cool them completely.
Store the cookies in an airtight container for upto 1 week. This recipe makes 60 to 72 cookies.
Bakeru2019s Note : You can buy pre-made vanilla sugar in gourmet food stores and online merchants. Make sure theyu2019re gluten-free.