I am making cookies from this (Dorie Greenspan) recipe. I did not add the nuts but other than that I followed the recipe to a T including chilling the dough for an hour before scooping it. After 10 minutes in the oven I have a tray full of co-joined cookies! I have returned the dough to the refrigerator and wait with digits crossed for someone to suggest a solution. The trays are lined with Silpat. My oven temperature is good. I just checked it.
Edited to add they are not even firming up as they cool.