There are eight basic types of cookies: bar cookies, drop cookies, fried cookies, molded cookies, no-bake cookies, refrigerator (ice box) cookies, rolled cookies and sandwich cookies. You can see the overview of the different types of cookies, or read the individual listings in this glossary.
Most homemade cookies will maintain their taste and texture for up to 3 days. If you leave them out for too long, the cookies begin to harden or dry out. To prevent cookies from becoming stale, cover them with plastic wrap or keep in an airtight container
Vanilla extract is not necessary in terms of the structure a baking recipe. However, leaving it out of a recipe will change the flavor. Vanilla extract enhances the flavor in cookies, cakes, and muffins and other recipes