Mrs Fields Chocolate Chip Cookies

1 cup (2 sticks) softened butter
1/2 cup granulated sugar
1.5 cups packed brown sugar
2 eggs
2.5 teaspoons vanilla extract
2.5 cups all-purpose flour
3/4 teaspoon salt
1 teaspoon baking powder
1 teaspoon baking soda
1.5 twelve-ounce bags semisweet chocolate chips

1. Preheat oven to 350 degrees.
2. In a large mixing bowl, cream the butter, sugars, eggs, and vanilla.
3. Sift together the flours, salt, baking powder, and baking soda.
4. Combine the wet and dry ingredients.
5. Stir in the chocolate chips.
6. With your fingers, place golf-ball-size dough portions 2 inches apart 
on an ungreased cookie sheet.
7. Bake for 9 minutes, or until edges are light brown.

Tidbits:
It's very important that you not exceed the cooking time given above,
even if the cookies appear to be underbaked.  When the cookies are 
removed from the oven, the sugar in them will stay hot and continue the
cooking process.  The finished product should be soft in the middle and 
crunchy around the edges.
For variations of this recipe, substitute milk chocolate for the semisweet
chocolate and/or add 1.5 cups of chopped walnuts or macadamia nuts to the 
recipe before baking.  Although you can substitute margerine for butter in
this recipe, you will have the best results from butter.  The cookie will 
have a richer taste and will be crispier around the edges like the origional.

Source:
Top Secret Recipes - Todd Wilbur.