Of all the suspicious ingredients to add to cake batter, mayonnaise is certainly at the top of the list. Known for adorning meat-laden sandwiches and turning everything from eggs to Jell-o into a “salad,” mayo doesn’t seem like a customary ingredient for brownies, yet here we are.
Yes, baking with a scoop of mayonnaise can improve your baked goods, and it can serve as a substitute for eggs and fats in a recipe. Sometimes. But before you order that 16-liter tub of Hellmann’s from Costco to serve as an all-purpose butter replacement, you need to understand what butter accomplishes in a recipe, and why (and when) it can’t be so easily swapped out.
When can mayo replace butter in baked goods?
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Mayonnaise, at its simplest, is a silky emulsion of eggs, acid (like vinegar or lemon), and oil. When you break it down to its roots, you can see why it makes sense in baking. Its components make it a perfectly suitable substitute for oil, its thick and creamy constitution is similar to that of softened butter, and since it already has eggs in it, mayonnaise exhibits some of the binding power of eggs when cooked.
Mayo works best as a butter substitute in doughs and batters when butter isn’t the star flavor, when they get their structure from somewhere else (like flour), and when the butter isn’t doing something incredibly important (more on that later). Cake batters, brownie batters, cookie doughs, and dinner rolls can work with the richness mayo has to offer. The mayo will fulfill its duties and lend plenty of moisture and richness to the finished dish.
When you can’t use mayo as a butter replacement in a recipe
There are some desserts that simply need butter. Nothing else will do. This is because butter plays several important roles in a lot of recipes. Butter not only aids in creating emulsified batters, but can help trap air and carbon dioxide, provide structure, increase texture, extend shelf life, add water, contribute that alluring golden-brown color, and, of course, provide that mouthwatering flavor and aroma. (Read more about the science of butter in this blog from my alma mater, the Institute of Culinary Education.)
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Put down the jar of mayo and pick up a stick of the good stuff for recipes that rely on butter for flavor, structure, or providing a textural reaction in the oven. In shortbread cookies—and many other high-ratio, butter-forward cookies—it accomplishes all three of those jobs. The flavor, structure, and texture are all on blast in a shortbread cookie, and if one of them is off, then you’ll have a lot of disappointed shortbread fanatics to answer to.
Mayonnaise cannot be used for butter in viennoiserie either. If you happen to be laminating dough at home and you come up a half a pound of butter short, drop your rolling pin and get some more, because mayo can’t save you. Ditto when making danish dough and puff pastry. Butter provides a necessary reaction in recipes where the butter is manipulated to create layers in the dough. Butter always contains a percentage of water, and when the butter melts in the oven, the water is available to evaporate. When it evaporates, a butter-coated air pocket is left in its wake. Multiply these air pockets hundreds of times and the croissant, palmier, or cheese stick expands to around three times its previous size. Sorry mayo, but butter’s got you beat there.
Similarly, butter must be used for flaky pie crusts, flaky biscuits, or anything else with “flaky” in the title. The butter gets worked into the flour of these short doughs and prevents the flour from absorbing too much water. The butter seals some of the flour and keeps the dough from developing too much gluten, keeping the texture short. This, combined with plenty of small butter pockets, is what gives flaky dough its flake. Mayonnaise isn’t a saturated fat that can be manipulated the way butter can. Instead of creating pockets, the mayo will just blend into the dough.
For mayo-dessert newcomers, stick with recipes that explicitly include mayonnaise in the recipe, or stick to the 1:1 replacement ratio for cake batters. If you fear your cookies will end up tasting like a ham sandwich, worry not; the mayonnaise-y flavor will be diffused among the numerous other ingredients, and further mellow after baking.
A mayo cookie recipe that actually works
The following recipe actually uses light mayonnaise (I know, I really pushed the limits with questionable ingredients this time) to replace both butter, eggs, and salt in a walnut chocolate chunk cookie, but you can use non-light mayo, too. I gave a few of these cookies to my boyfriend, but knowing my line of work, he asked me what “the deal” was with them. When I told him they were made with mayo, and I could see his panic synapses begin firing. He tasted one and quickly relaxed, pleasantly stunned. (Honestly, same.) This cookie recipe has no business being as good as it is, and I never would have believed that I would tell people a mayonnaise chocolate chunk cookie is quick, easy, and delicious. But here we are.
Mayonnaise Walnut Chocolate Chunk Cookies
Makes 1 dozen cookies.
Ingredients:
- ¼ cup light mayo (I used Hellmann’s)
- ¼ cup + 2 tablespoons white sugar
- ½ teaspoon vanilla extract
- ½ cup flour
- ¼ teaspoon baking powder
- ¼ teaspoon baking soda
- A pinch of cinnamon
- ⅓ cup chopped walnuts
- ¼ cup chopped dark chocolate
Preheat the oven to 350°F. Line a baking sheet with parchment paper.
In a small bowl, combine the dry ingredients. In a separate small bowl, mix the mayonnaise and sugar together until combined. Add the vanilla.
Pour the dry ingredients into the sugar-mayo mixture and mix until almost combined. Add the chopped walnuts and chocolate. Mix until combined.
Scoop tablespoon sized mounds onto the baking sheet. Bake for 15 minutes at 350°F. Cool, and enjoy the tastiest mayonnaise cookies you’ve had, maybe ever. This recipe can be doubled, if desired.