I’m a peanut butter fanatic, and I feel uneasy if I don’t have an extra jar or two of the stuff stashed away “just in case.” So you might be surprised to learn that peanut butter cookies haven’t always been my first choice for spur-of‑the-moment baking. After all, the cookies’ other ingredients are constants in my kitchen, too. But the truth is that I enjoy most peanut butter cookies only when they’re warm and fresh. As they cool, so does my enthusiasm.
I wanted to think that a solution to this flaw would come easy to a peanut butter devotee such as myself. But after weeks of trying to devise a recipe for cookies with robust peanut flavor and lasting chew, I had to admit that a fix was anything but easy—and was not, as I’d initially hoped, simply a matter of packing more peanut butter into the dough (read on to find out why). When I did finally nail a formula that produced soft, chewy, deeply nutty cookies, I humbly realized that the trick boiled down to a subtle but fundamental point of baking: ratios.
I decided to focus on producing a chewy texture first, and luckily I was on familiar ground. Several factors contribute to chewiness in cookies (including adequate amounts of sugar and moisture), but fat is also key. While developing a brownie recipe years ago, I discovered that boxed‑mix brownies get their beguilingly chewy texture from a specific ratio of saturated fat to unsaturated fat in the batter: 30 percent saturated to 70 percent unsaturated. Since then, I’ve applied that fat ratio to recipes for both sugar and oatmeal cookies with great success. So I figured all I had to do was bend the traditional peanut butter cookie formula to fit the chewiness template and I’d be done.
The typical peanut butter cookie recipe I used as a starting point called for 1 cup each of butter (melted to make mixing easier) and peanut butter and 2 cups of flour. After whisking the butter and peanut butter together along with granulated sugar, eggs, and vanilla, I stirred in the flour, baking soda, and salt. Then I scooped equal portions onto a baking sheet, used a fork to imprint the tops with the cookie’s characteristic crosshatch pattern, baked them, and let them cool briefly.
With all that butter, 56 percent of the fat in the dough was saturated, producing a cookie that was tender and short instead of chewy; it also lacked nutty flavor. Most of the fat in peanut butter is unsaturated, though, so replacing 1/2 cup of highly saturated butter with an additional 1/2 cup of peanut butter would not only boost peanut flavor but also lower the saturated fat to a more favorable 35 percent.
But by the time I had a cohesive dough, I could tell that this formula wasn’t going to work. The mixture was so stiff I was practically kneading it, and the cookies themselves hardly spread at all in the oven and emerged dry and cracked at the edges.
I suspected that peanut butter–butter swap was to blame for the stiff, dry results. Butter is mostly pure fat (it’s also about 20 percent water), but peanut butter contains protein and starch. According to Lisa Dean, research food technologist at the U.S. Department of Agriculture’s Agricultural Research Service, the protein in peanut butter swells and absorbs added water: This phenomenon was surely drying out my cookies. But the peanut butter’s dry-matter content was potentially useful: If I could rely on peanut butter protein and starch instead of some of the flour to give my cookies structure, maybe I could prevent the cookies from drying out and gain more robust peanut flavor in one fell swoop.
But decreasing the flour to 1 1/2 cups only got me part of the way to my goal. The dough was softer, the cookies spread more, and their flavor improved, but biting into the cookies caused them to crumble, and overall they were now more tender than chewy.
It took a few more tests, but I finally figured out that the absolute limit on the ratio of peanut butter to flour was 1 cup to 1 1/2 cups, respectively. Any more peanut butter and the cookies didn’t have enough flour for gluten development, which left the cookies too crumbly.
But that satisfying chew still eluded me until I realized that, in general, fat acts a tenderizer in baked goods. Was it possible that my recipe simply had too much fat overall? To find out, I dropped the butter from 1/2 cup to 1/4 cup. This not only brought the saturated/unsaturated fat ratio back to the ideal 30/70 split but also decreased the ratio of total fat to other ingredients, yielding a supremely chewy cookie.
The chewy cookie lover in me was completely satisfied. The peanut butter fanatic was not, though I wasn’t about to touch my carefully calibrated dough formula to pack in more peanut flavor. Instead, I went straight to the source and added ½ cup of finely chopped dry-roasted peanuts to the dough after mixing in the dry ingredients. Their richness and crunch added the depth I was looking for without affecting the fat ratio or interfering with the texture of the dough, but they left the cookies tasting a bit savory. Substituting dark brown sugar for white sugar and adding 2 tablespoons of honey tilted things back in a sweet direction and had the added benefit of enhancing the chewiness a little more.
One final tweak: With the chopped peanuts clearly advertising the cookies’ identity, I decided to abandon the crosshatch. While it’s up for debate why peanut butter cookies traditionally bear this mark, I’ve always suspected that it’s because the stiff dough needs to be firmly pressed down for the cookies to spread properly. But because my dough was softer than the typical peanut butter cookie dough, it spread nicely if I simply pressed it with my fingers after portioning it on the baking sheet. (For more information, see “A History of the Crosshatch.”)
Now that I have an easy, truly satisfying peanut butter cookie recipe at the ready, I should probably add another jar or two of peanut butter to my stash. Just in case.