This recipe makes a perfect chocolate chip cookie that is both chewy and crispy. It is from Dorie Greenspan's excellent cookbook, "BAKING: From My Home to Yours". Including nuts is highly recommended. Some variations: for chocolate chocolate chip cookies, substitute 3/4 cup of flour for 3/4 cup unsweetened cocoa powder; for espresso chocolate chip cookies, add 1 1/2 tablespoons espresso powder after the vanilla extract; for a coconut version, add 1 1/2 cups sweetened (toasted or untoasted) shredded coconut when adding the chocolate chips; and for peanut butter chocolate chip cookies, substitute 1/2 cup of peanut butter for 1/2 a stick of butter and beat them together before adding sugar (and use peanuts). Enjoy! Note: The dough can be covered and refrigerated for up to 3 days, or frozen. If you'd like, rounded tablespoonfuls of dough, ready for baking. Freeze the mounds on a lined baking sheet, then bag them when they're solid. There's no need to defrost the dough before baking-just add another minute or two to the baking time.