Servings: One 9-inch (23 cm) square pan, which cuts into about 25 bars
¾ cup (175 g) unsalted butter at room temperature
⅓ cup (70 g) packed light brown sugar
1 tsp (5 ml) vanilla extract
1⅓ cups (175 g) all-purpose flour
¼ cup (40 g) cornstarch
½ tsp (2 ml) salt
1 cup (180 g) chocolate chips
1. Preheat the oven to 325°F (160°C) and lightly grease a 9-inch (23 cm) square pan and line it with parchment so that the paper comes up the sides.
2. Cream the butter and brown sugar together with the vanilla until light & fluffy. Sift the flour, cornstarch and salt over the bowl and stir in the flour until evenly incorporated. Stir in the chocolate chips.
3. Spoon the dough into the prepared pan and press flat. Dock with a fork and then bake for about 50 minutes, until golden brown around the edges.
4. Let the shortbread cool for 5 minutes, then slice it into squares before cooling completely.
The shortbread will keep in an airtight container for up to a week.