If you can put your hands on it, Alton Brown did a Good Eats episode on this very subject....Three Chips for Sister Martha. He basically took the generic toll house cookie recipe and varied it to get a thin cookie, a chewy one, and a puffy one.
I'm a dork and I love cookies (and Alton Brown - yummy!), so I took notes. Alton said that a batter with extra baking soda means a thinner cookie. My notes are kind of sketchy here, but I think that baking soda is acidic, and the more acid in the cookie, the thinner it will be.
For a chewy cookie, use melted butter and bread flour to get a chewy cookie. The water and the wheat protein make gluten which is chewy. Also, the darker the sugar you use, the chewier the cookie will be.
If you prefer a puffy cookie instead, use butter flavored shortening instead of butter. It melts at a higher temperature, stays solid longer so batter can rise and set before it spreads. Use regular AP flour for this one, because the AP flour soaks up less moisture which means more steam. Steam lifts the batter which provides the "puff"
If you're not already doing it, make sure you use the two bowl method - cream your shortening (or butter) with your sugar, add your eggs and vanilla, and in a separate bowl mix the dry ingredients. Slowly add the dry ingredients to the wet bowl and mix well.
Alton also says to chill your dough before making the cookies, but at my house once the mixer cranks up for cookies, the game is ON, so we never wait while the dough cools.
Anyway, all three recipes are on the Food Network website (www.foodtv.com
). Good luck!
And take heart, a flat cookie is still yummy when you dunk it in milk!