While
silpats and parchment paper are interchangeable in some recipes, I don't recommend using parchment here, as the silpat helps insulate the cookies from the pan's heat; when made with parchment, the cookies are less chewy and brownie-like. The cookies are very delicate when freshly baked, so use your thinnest, most-flexible spatula to transfer from sheet pan to cooling rack; I'm partial to this whisper-thin
cookie spatula from OXO. Store cookies in an airtight container for up to 1 week, or freeze for up to 3 months.