Why are my cookies very, very crumbly? Will not hold their shape so now have a bowl of ice cream topping!

Thank you for that suggestion. I tried one at the early point of recommended time and they fell apart. I put them back in the oven and went other two minutes, but fell apart, and after another three minutes took them out and let them cool. Still crumbled into bits.
The second batch of the same mixed ingredients, I rolled into balls and pressed with a fork, left them in oven for full time, let them cool on tray, then cooling rack. These were a bit more stable but still fell into chunks and were dry and chalky. I will try a different recipe and see if it is just my baking skills.