I attempted to make cookies a few nights ago that were both Me Friendly, and not insulting to my guest, h.b. (i.e., in my recipe 1/2 of the butter is actually applesauce, and the other half is half-non-existent). They were delicious, but, as you might imagine, are always somewhat cakey.
Incidentally, both H.B. and h.b. have iron stomachs and the superhuman skill of being able to, without flinching, eat combinations of unhealthy food that I couldn't even think about without getting nauseous. I, therefore, made a second batch with 2 whole freaking sticks of butter to satisfy my two house companions.
You might notice they came out a bit flat.
This is what happens when you adjust the amount of butter in your recipe, but neglect to account for the fact that to keep the recipe balanced you must also adjust butter's rivaling ingredient (i.e., flour). When you neglect Le Chatelier's principle when baking cookies, my friends, you get a mouse. Sprinkled, no less. It helps if the rack in your oven is a bit crooked.
The third batch was perfect, btw. And contained copious amounts of oatmeal and raisin.