1/2 cup granulated sugar
1 tsp pure vanilla extract
1 3/4 cups all purpose flour
1/4 cup cornstarch
1 cup whole pistachios
Cream the butter and the sugar together. Beat in the vanilla. Whisk together the flour and cornstarch. Blend them into the butter and sugar, until it forms a dough. Stir in the pistachios and make sure you get them well distributed in the dough. Turn the dough out onto a sheet of plastic wrap and form it into a log, about 9 or 10 inches long. Wrap it in the plastic and smooth it into a uniform smooth shape, twisting the ends to secure. Refrigerate the dough for at least 3 hours, or overnight. Set oven to 350F. Slice the dough into 1/4 - 1/3 inch slices and place on a parchment or silpat lined baking sheet. Thinner slices will bake up crispier, and thicker ones will be more buttery and soft. Bake for about 10 minutes, maybe a little longer for thicker cookies. The cookies will still be pale and soft, but will firm up as they cool. Cool for 2 minutes on the baking sheet, then cool completely on a rack.