These are large chewy cookies, but you must follow the steps exactly if you want good results. I know some of the steps sound very picky, but any variation in the process will result in a different cookie.
First, use high quality ingredients. Butter means butter, vanilla means real vanilla, chocolate chips should be quality name brand.
Preheat the oven to 325 degrees Fahrenheit.
1.5 cups brown sugar
1 cup white sugar
1.5 sticks butter (real butter) partially melted
1 teaspoon baking powder
2 teaspoons vanilla (real vanilla)
1 extra large egg
2 1/3 cups plain flour (not self rising)
6 ounces semi-sweet chocolate chips
6 ounces milk chocolate chips
Add the vanilla--away from the baking powder. Do not let the vanilla touch the baking powder.
Mix for 90 seconds using medium speed on a mixer.
Mix for two minutes. This mixture will be very thick--dry. It will look like there is not enough moisture to hold things together. If you have a low quality mixer, it may stall or burn up.
The cookie should be two inches in diameter, 3/4 inch thick. Mash the cookie down with a spoon. It should not be a ball, but look more like a tire.
Cook for 13 minutes and 30 seconds.
Immediately remove the cookies to a plate for cooling--they will continue cooking if you leave them on the sheet.
Wait until the cookie sheet has returned to room temperature before you add the next batch of dough.
This makes about 30 cookies.