This is the second year in that I've attempted to make palmiers from scratch. Everything seems to go well until I pop them in the oven, when they start to unroll. They taste great, but they look pretty rough. I've tried freezing the shaped palmiers and popping them in the oven directly from the freezer, and I've also tried shaping the cookies, then mashing them with the heel of my hand to get the layers to stick together a bit, but they still unroll. Any thoughts as to what might be happening?