Many people believe that pancake batter needs to rest before cooking, but this is actually not the case. Pancake batter can be used immediately after it is mixed together. There is no requirement to let it sit and rest. Pancake batter only needs to be mixed until the ingredients are combined. Over-mixing the batter can result in tough pancakes. So, once the batter is mixed, you can go ahead and start cooking your pancakes. There is no need to let the batter rest first. Of course, if you want to make sure your pancakes are nice and fluffy, you can always let the batter sit for a few minutes before cooking. This will allow the flour to absorb some of the liquid and expand, resulting in fluffier pancakes. But if you're in a hurry, there's no need to let the batter rest. Just go ahead and start cooking!