Costco has a new cookie that's sure to delight even the most ardent of chocolate lovers -- a double chocolate cookie.

A step-by-step guide to absolutely perfect double chocolate cookies. Follow the steps below for beautifully symmetrical cookies with just the right amount of chewiness, or see the recipe tips for ...

To double this recipe: Omit the egg yolk and use 3 large eggs instead; double the amount of the remaining ingredients. This will yield an excess of cookie dough so you may need to fold in the ...