To slice soft bread very thin, about the only thing to do is to freeze it, slice it and defrost it. Small amounts of very stale bread can, of course, be used to make bread crumbs. Let cool outside the oven for 5 minutes. Unwrap and it should come right out of the pan. Remove the pot or pan from the heat at once.
Speed is of the essence.
Using a wooden spoon, preferably, remove all ingredients that don't cling, and transfer to another pot. Taste the food. Taste it again. If the sheet is half or less full of cookies it may absorb too much heat and get too hot. Put an inverted baking pan on the empty half.