Butter

The first and foremost ingredient in cookie recipes. It’s true that not every cookie recipe contains butter, but most do and it’s important not to skimp. Use good, fresh unsalted butter; it provides a fragility, a depth of flavor, and a delicacy that no other fat can duplicate. By the way, there are a few recipes that call for oil—for those use a mild, bland oil, such as canola, peanut, or corn oil.