1 cup (2 sticks) butter, room temperature
1/2 cup powdered sugar
1 1/2 cups flour
1/2 cup cornstarch
1/4 teaspoon fleur de sel or coarse grained salt
1/2 cup dark chocolate, cut into small pieces
1. Cream the butter and sugar.
2. Mix in the flour, cornstarch and salt.
3. Mix the dry ingredients into the wet ingredients followed by the chocolate.
4. Shape the cookies as you like and place them on a parchment lined baking sheet with an inch of space between them.
5. Place the baking sheet in the fridge and chill for at least 30 minutes.
6. Bake in a preheated 350F oven until they just start to turn a light golden brown, about 8-14 minutes, remove and let cool. (Note: The shortbread will still be rather soft when it is done but it will crisp up as it cools.)