Rock Hard Cookies!

I have been baking cookies for as long as I can remember and this is the very first time I have had this problem. The recipe was for Toll House Choc Chip Cookies..ymmmmm

I doubled the batch; every cookie was the same size (not accomplished very often)
they were beautiful. I didn't try the cookies after they had cooled; luckily it was a very good friend that sampled the cooled off cookies. "Man, these are really HARD
cookies!" This friend has been eating my cookies for over 20 years... I wasn't really listening to him...I went to break off a piece and nearly broke my fingers.
These cookies were not over baked hard, not crispy hard, they were JUST HARD!

You know if this ever happens with cookies being over baked you can place a slice of fresh apple in the container with the cookies and they will soften up. Well, I tried this little trick and my cookies remained hard. I figured maybe one slice of apple wasn't enough for about 6 dozen cookies. I sliced about another 1/2 of an apple and placed the slices skin side down on top of the cookies. YES!..after about 4 hours the cookies became edible. ( I had a plan to use these rock hard cookies like biscotti if the apple trick didn't work.)

In the mean time I had called my friend who is a dietitian and asked her about the little ordeal with my cookies. She immediately knew what the problem was..did you use too much baking powder? Ah Ha! When I was putting together the recipe I put in BAKING POWDER instead of BAKING SODA. Luckily I caught my mistake before I mixed the ingredient in. I scooped the BAKING POWDER out and replaced it with BAKING SODA.
Guess I didn't get all the baking powder out.

I don't know the scientific whys of how BAKING POWDER makes rock hard cookies; but I'll never make that mistake again.

Hope this helped someone's cookies. Kako