Cardamom Ginger Spiced Shortbread Fingers

Steps

1. Line an 8-inch square baking pan with parchment, leaving an overhang on two sides.
2. In a small bowl, stir together the granulated sugar and one third of the cinnamon to make the topping; set aside.
3. In a medium bowl, whisk the flour, cornstarch, cardamom, ground ginger, the remaining two thirds of the cinnamon and the salt.
4. In a large bowl, beat the butter, powdered sugar and brown sugar until creamy and pale, about 3 minutes, then beat in the vanilla.
5. Add the flour mixture to the butter mixture and mix on low just until a soft, crumbly dough comes together.
6. Press the dough evenly into the lined pan, smooth the top, and prick it all over with a fork. Chill for 20 minutes.
7. Meanwhile, preheat the oven to 325°F (165°C).
8. Sprinkle the cinnamon-sugar topping evenly over the chilled dough.
9. Bake for 30 to 35 minutes, until the edges are golden and the center is pale golden and set.
10. While still warm, cut into 12 fingers with a sharp knife, then cool completely in the pan, about 30 minutes, before lifting out and separating.