8 tablespoons unsalted butter, softened
1/3 cup soft light brown sugar
1 3/4 cups all-purpose flour
1 teaspoon ground cardamom
1-inch piece peeled ginger, finely grated
Seeds of 1 vanilla bean
1 tablespoon egg white (about half of the white from 1 large egg – freeze the rest of the white and yolk separately for later use)
Pinch of salt
2 tablespoons milk
Preheat the oven to 325°F. Line the base of an 8-in square glass pan with baking parchment.
Using an electric mixer fitted with the beater attachment or by hand with a wooden spoon and in a large bowl, cream the butter and the sugar together until combined. Add the flour, ground cardamom, ginger, vanilla seeds, egg white, salt, milk and 1 tablespoon of cold water and mix everything together.
Put the mixture into the pan and spread it out, then flatten evenly with your hands. Use a sharp knife to mark the shortbread into 16 even-size rectangular pieces (4 x 4). Bake in the oven for 40–45 minutes or until the shortbread is a light golden brown and firm, but with a slight softness to the touch – do not over bake or the cookies will dry out.
Once cooked, remove it from the oven and use the sharp knife to cut through the squares. Leave to cool completely before carefully removing from the pan.
Adapted from seriouseats.com