The recipe below is the famous Toll House recipe with 3 changes: I double the vanilla, increase the flour by 1/4 cup and substitute dark brown sugar for light. The dark brown sugar substitution is pretty much a given for most anything I cook. I personally like my cookies to be a little thicker than the normal recipe, and the extra flour gives the cookie a little more body in addition to compensating for the extra vanilla and changes introduced by the dark brown sugar.
Preheat Oven to 375° F
1 cup butter, softened
2 eggs
3/4 cup granulated [white] sugar
3/4 cup packed brown sugar
2 teaspoons vanilla extract
2 1/2 cups all-purpose flour
1 teaspoon baking soda
1 teaspoon salt
1 bag of dark chocolate chips (variation: 12 oz. bag of M&Ms)
Bake 11 to 13 minutes or until golden brown. Let stand for 1 - 2 minutes on cookie sheets before transferring wire cooling racks. Use a swift motion with spatula to cleanly remove the cookies from the cookie sheets.