Christina's Brown Sugar Shortbread

One pound of butter
One pound of flour (about 3 1/2 cups)
1/2 pound of brown sugar, packed (about one cup)
1/3 cup of cornstarch
1 tsp of salt if the butter is unsalted
1 Tablespoon of vanilla.

Combine dry ingredients in a food processor. Add butter at refrigerator temperature, vanilla, and process until a clump forms.

Chill in flat rounds. Roll out chilled circles (not too think) cut into shapes and freeze before baking. Warm the oven to 350 degree, put the frozen shapes on the cookie sheet lined with parchment paper, and bake for 15 minutes.