[Aline]

FYI

Cookie sheets also make a big difference in how your cookies with turn out. Cookie sheets without edges is best because the heat "surrounds" the cookie, which makes for better baking. Cookie sheets with edges allows heat over the top of the cookie only.

My mother couldn't figure out why her cookies were always very dark on the bottom. She lowered her oven temperature, reduced the baking time, etc. One look at her cookie sheet and I knew why. It was too "thick" and had edges. She tried my cookie sheet, which is thin and has no edges (totally flat), and her cookies turned out great!