Are your cookies raw in the middle, or have they become hard? How to tell when cookies are done is partly a matter of taste because what's crispy to some bakers is overdone to others. Just a minute or two in the oven separates gooey cookies from cookies that are still raw in the middle or crispy cookies from those that are too far gone. Fortunately, there are several ways to check if cookies are done to avoid these cookie catastrophes.
Set the Timer for the Minimum Time
First, before baking cookies, use an oven thermometer to make sure your oven is actually the temperature that is given on the oven dial.
Always check on cookies at the minimum time given in your recipe. You can easily cook them longer if necessary, but you can't "uncook" cookies that have baked too long and are now too hard or too brown. If they need a minute or two longer, be sure to reset the timer for those extra minutes. Thinking you'll just give them a bit longer without setting a precise time is a recipe for getting distracted and letting the cookies burn.
Lift to See the Bottom
Nearly all cookies will brown at least a little on the bottom while they cook, and some recipes even give you a color for which to look, such as slightly brown or light brown. For example, cookies like snowballs – also known as butterballs or Mexican wedding cookies – should not brown on top. The only way to know for sure that they're done is to roll one over and see that it's just slightly brown on the bottom.
Check the Edges
Many times, the recipe will tell you that the edges should be slightly brown or "just beginning to brown." Edges brown before the middle, so the edges can burn while the middle is still cooking. Some cookies – sugar cookies, for example – are best when the edges are set but not brown. You can check the edges visually without lifting the cookie, and with practice, you'll be able to see that the edges look more set than the center of the cookie, even when the edges are not yet brown.
If the recipe tells you to let the cookies cool on the cookie sheet for two minutes as chocolate chip cookie recipes do, that means the cookies will continue to cook while cooling because the sheet is still very hot. In these cases, you can experiment with the timing of removing the cookies from the oven.
The centers might look like they still need more cooking, and they will do that while they're resting on the cookie sheet. If you wait until the middle is totally cooked, you may find that your cookies are overdone after they cool on the cookie sheet.
Use the Toothpick Test to Know if Cookies Are Done
When cookies are thicker – like when baking brownies, which are essentially bar cookies – you can sometimes use a simple wooden toothpick to test and see if they're done. Insert the toothpick into the middle of the brownies or other bar cookie, and if the toothpick is free of cookie particles when you pull it out, they're done. In fact, they're probably done even if a few particles stick to the toothpick.
If it looks like batter is sticking to the toothpick, though, they're not done unless you're going for gooey brownies. If that's the case, only you can truly know when the brownies are done because cooking time depends on how gooey you like them. Just know that a minute is a long time to a cookie, and going from raw batter to gooey center can be the difference of only a minute or two.