For perfect sized cookies every time, do what the professionals do - use a stainless steel cookie scoop.  They come in 3 sizes, one to fit every need.

Best Big, Fat & Chewy Chocolate Chip Cookies

After years of using the recipe on the back of the chocolate chip package, and a few other variations, Robin's daughter Terryn discovered this recipe and it truly does make the BEST chocolate chip cookie we've met. These cookies are the pinnacle of perfection. If you want a big, fat, chewy cookie like the kind you see at bakeries and specialty shops, then these are the cookies for you!
 
Ingredients:
2 cups all-purpose flour (256 grams)
1/2 teaspoon baking soda
1/2 teaspoon salt
 
3/4 cup unsalted butter, melted (170 grams or 6 oz)
1 cup packed brown, sugar (220 grams or 7.75 oz)
1/2 cup white sugar (100 grams or 3.55 oz)
1 tablespoon vanilla extract 
1 egg
1 egg yolk
2 cups semisweet chocolate chips
 
Directions:

1.  Preheat the oven to 325 degrees F (165 degrees C). Line cookie sheets with parchment paper.

2.  Sift together the flour, baking soda and salt; set aside.

3.  In a medium bowl, cream together the melted butter, brown sugar and white sugar until well blended. Beat in the vanilla, egg, and egg yolk until light and creamy. Mix in the sifted ingredients until just blended. Stir in the chocolate chips by hand using a wooden spoon.

4.  Drop cookie dough 1/4 cup at a time with a 4TBS stainless steel scoop onto silicone baking mat or prepared cookie sheets. Cookies should be about 3 inches apart.

4.  Bake for 15 to 17 minutes in the preheated oven, or until the edges are lightly toasted. Cool on baking sheets for a few minutes before transferring to wire racks to cool completely