For Cookies With A Lusciously Soft Interior, You Need Egg Yolks

Cookies, the handheld sweet treat, need no introduction. Buttery and crisp, or chewy and sweet, and with fillings ranging from chocolate chips to peanut butter to cranberries, cookies have the distinctive ability to make anything that ails you right with a simple bite — we're talking the ultimate feel-good snack if there ever was one. But if you're looking to bake the most luscious chewy cookies that are rich and fudgy in texture and possess a delectable custard-like flavor, look no further than egg yolks. 

Central to recipes for ice creams, puddings, and dressings such as mayonnaise, egg yolks possess a higher fat content than whites, which are made of primarily protein and water and lend themselves to boosting the flavor and enriching the texture of your cookie with an airy consistency. So whether you're making a simple sugar cookie, or a riff off a classic chocolate chip cookie, adding additional egg yolks will elevate your cookie dough and deliver a light, chewy indulgence that's a departure from the typically dense, crumbly cookie model.

You can achieve a seriously delectable cookie with a rich, chewy center in just a few extra steps. First, you'll need to isolate your extra yolk. To separate the yolk from its white, you'll want to crack your egg and use your fingers to gently split it apart. Then, tilt the yolk carefully between the halves of the shell, letting the egg whites drip out — the yolk is what you want to hold onto. 

After successfully separating your yolk, beat and add to your creamed butter and sugar, and mix with an electric mixer. It's important to note that the more yolks you use, the fudgier the texture of your cookies, and the richer the flavor. But be sure not to go overboard — too much yolk in the dough means too much moisture and will result in spongy cookies. One to three yolks are sufficient to achieve that lusciously soft, moist center you want. 

These baking moves will collaborate beautifully to deliver a brownie-like texture that makes your cookies dreamy. Once your dough is ready, bake as usual and marvel at the richer color that develops while it bakes. 

There are plenty of other tips and tricks to bake successfully chewy egg yolk cookies. For example, you could swap out your white sugar for brown sugar (dark brown sugar has more molasses in it, thereby adding even more richness and moisture to your recipe) and use butter with a higher butterfat content, such as European butter, which typically possesses 82 to 83% butterfat, or Amish butter, which is around 84% butterfat.

Additionally, to ensure they remain optimally chewy, you can chill your cookie dough for four hours or so before baking to keep your cookies from spreading too much. The flavors in chilled cookie dough will also have melded a bit more, allowing you to taste the full enhancements of the egg yolks.

And be sure to keep your eye on your cookies while they're in the oven, as it's important that you don't overbake them. Note that they will be slightly puffed up due to the extra yolks, but since they will continue to bake as they cool, you'll want to make sure the centers are slightly undercooked when you take them out of the oven. And when you want to dig into those leftover cookies (assuming you didn't eat them all at once), be sure to pop them in the microwave for about 10 seconds so you can bite into that delectable gooeyness you worked to achieve.