Posted by Cathy M
From a retired Home Ec teacher - don't change the recipe.Be sure you cream the butter & sugars till light & fluffy (I use a stand mixer) & chill dough at least 2 hrs, preferably overnight. Use a scoop & make sure cookie sheets are cold as well.
Bake one sheet at t time - on center oven rack, 9 - 11 min., cool 2 min or just until set on sheet, then finish cooling on a rack. If they get too cold & won't come off, return sheet to oven for a minute or two.Good luck! P.S. check out Alton Brown on food network for variations for chewy or crisp variations & the science behind them)