Flourless Peanut Butter Chocolate Chip Cookies

"I can't seem to stop making these, and as I make them, so they get eaten. Luckily, they are extraordinarily easy to throw together. And, incidentally, they are gluten- and dairy-free. Do check the ingredients list on the peanut butter if you do absolutely need this to be gluten-free (were you to be baking them for a coeliac, for example) as brands vary. I'm afraid health-food-shop-type peanut butter doesn't work here. These do soften if left overnight — though there are those who actively prefer them this way —..."