How much vanilla should I use in this chocolate chip cookie recipe?

[Hannah]

How much vanilla should I use in this chocolate chip cookie recipe?

3/4 cup of granulated sugar
3/4 cup of packed brown sugar
1 cup of butter or margarine, softened
1 egg
2 1/4 cup of all purpose flour
1 teaspoon of baking soda
1/2 teaspoon of salt

1 package of chocolate chips

Also, ANY recipe for thin, crispy, and chewy cookies would be awesome(: I have been searching everywhere for a recipe like that and I am trying this one tonight. I'd also love some tips because I am new to cooking and I'd like to learn more! Thanks <3

[KarenL]

Use a teaspoon of vanilla. Go to sunset.com and look at their article on "the perfect chocolate chip cookie". They have a thin, crispy, chewy recipe. Pay particular attention to the baking time and temperature. Bake those cookies a few minutes too long and they will no longer be chewy but merely thin and crisp, though they will soften in a day or two if left out in the air. And when they say to cool the melted butter to room temperature, they really mean it. Melt the butter at least half an hour ahead so it has time to cool. Use it a bit warm, as I did once, and the cookies come out completely different than they were supposed to.

[horselover]

You don't have to add vanilla but if you do I would use 1 teaspoon.