The recommended resting time for cookie dough varies from recipe to recipe. But according to The Kitchn, the decision can ultimately depend on what you’re hoping to achieve. “If all you’re looking for is less spreading, a quick 30 minutes should suffice,” explained the publication. However, if you’re hoping to cultivate a more complex flavor (i.e., help your cookies taste better) and better browning in your final product, you’ll likely need longer. The Kitchn recommends a full 24-hour resting period in the fridge, while other sites, such as Taste of Home, claim that overnight is all you need.
However, per The Kitchn, it is important to remember that not every cookie dough benefits from ripening. In general, recipes “that [rely] on eggs to provide the bulk of the liquid content” — such as chocolate chip or sugar cookies — usually improve from a rest period. That being said, always defer to the recipe instructions. If the recipe calls for no resting period, you can be assured it’s not a mistake.