Preparation Steps

• Preheat the oven to 325°F (160°C). Line an 8-inch square pan with parchment paper, leaving an overhang to lift the shortbread out later.
• In a large bowl, beat the softened butter and powdered sugar together until light and fluffy, about 2–3 minutes.
• Add the vanilla extract and mix until incorporated.
• Sift the all-purpose flour, cornstarch and salt together. Gradually add the dry ingredients to the butter mixture and mix on low until a soft dough forms. Do not overwork.
• Press the dough evenly into the prepared pan, smoothing the top with the back of a spoon or your fingers. Prick the surface lightly with a fork to allow steam to escape.
• Chill the pan in the refrigerator for 10–15 minutes to firm up the dough for an even bake.
• Bake for 18–22 minutes, or until the edges are just turning a light golden color. The center should still be pale.
• Remove from the oven and allow to cool in the pan for 10 minutes, then lift out using the parchment overhang and transfer to a wire rack. Slice into 12 pieces while still slightly warm or after cooling completely.
• Serve plain or dust with additional powdered sugar if desired.