Icebox cookie dough, by design, needs to be really well chilled (often fully frozen) before it's baked. u003cbr/u003eu003cbr/u003e1) This u003cstrongu003efully re-solidifies the butteru003c/strongu003e before the bake, which will help the cookies to maintain their structure and round shape in the oven. Essentially, it'll help them not turn into cookie pancakes.u003cbr/u003eu003cbr/u003e2)The rest time in the fridge also u003cstrongu003eallows the flour to hydrateu003c/strongu003e which stabilizes the dough further.u003cbr/u003eu003cbr/u003e3) Only once the log is fully chilled, will it stand up to slicing. Thus, that long chill is u003cstrongu003erequired to portion your cookies using the slice and bake method u003c/strongu003eas opposed to a roll and cut-out method.