You might be tempted to bake 2 sheets of bars at a time in the upper and lower thirds of the oven. Don't give in to this urge—they must go in the middle of the oven to cook through and brown evenly.
Cooks' note:
· Cookies keep, layered between sheets of wax or parchment paper and chilled in an airtight container, 2 weeks.
- Available at supermarkets and some supermarkets.