Buckingham Palace Shortbread

2 c. unsalted butter, at room temperature
2/3 c. granulated sugar
4 c. pastry flour
1 1/3 c. cornstarch
Superfine sugar for sprinkling


In a large bowl, cream the butter and sugar together until pale and fluffy. In a medium bowl, stir the flour and cornstarch together. Gently mix the flour mixture into the butter mixture until it forms a soft dough. You can usually do this with a hand mixer until there is about 3/4 cup of flour mixture left then you will have to stir that in or work in with your fingers. Cover the dough with plastic wrap and refrigerate about 15 minutes, or until firm.

Preheat oven to 325 degrees.

Dust dough lightly with flour and roll it out to 3/4-inch thick square on a sheet of parchment paper. Transfer the parchment paper and dough to a baking sheet. Bake in the center of preheated oven for 30-40 minutes, or until lightly golden and firm to the touch. Remove from oven and sprinkle generously with superfine sugar. While still warm, use a paring knife to cut the shortbread into 48 pieces.