Cupcake Project Substitution Lab, Test 1: Using Mayonnaise as an Egg Substitute

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Mayonnaise Instead of Eggs

Test 1: Using Mayonnaise as an Egg Substitute

Introduction / Purpose

Mayonnaise is mostly egg yolk and oil; so, despite the initial “yuck” factor, mayo is sometimes suggested as a substitution for eggs in baking. The most famous example of baking with mayonnaise is the chocolate mayo cake – proclaimed to be extra-moist. I wanted to know how mayonnaise would work as a substitution for eggs in desserts other than chocolate cake. Would I be able to taste the mayo? How would it affect the consistency of the dessert? Is mayonnaise a viable alternative to eggs? I decided to run some tests in my substitution lab (a.k.a. my kitchen). My hypothesis was that the substitution would be successful, but taste would be compromised.


To perform my tests, I used full-fat organic mayonnaise. (View on Amazon) [paid link]


I used a substitution amount found on Allrecipes: 3 tablespoons of mayonnaise in place of 1 egg. I used two tried and true recipes, Ultimate Vanilla Cupcakes and Toll House Chocolate Chip Cookies. Both recipes contain two eggs and I replaced the two eggs in each recipe with 1/4 cup plus 2 tablespoons of mayonnaise.


Eggs vs Mayo in Cupcakes

Mayo instead of eggs in cookies

Results and Discussion

The mayo had a huge impact on the Ultimate Vanilla Cupcakes. The cupcakes didn’t dome, they weren’t quite as light, and the taste wasn’t Ultimate. The cupcakes did NOT, however, taste like mayo – they were still quite good. I frosted them with vanilla bean buttercream frosting, served them to several unsuspecting test subjects, and no one talked about an odd flavor.

The mayonnaise worked extremely well in Toll House Cookies. The cookies were just as tasty – if not better – than the original Toll House recipe. The cookie dough didn’t stick together as well as Toll House dough typically does, and I didn’t think the cookie dough tasted as good (as many people eat cookie dough, this is important to consider). However, once baked, there was no hint of mayo and the cookies were fantastic!

Important: Do not try to use mayo in your frosting. I tried that as a separate experiment and the taste and smell were gag-inducing.


Based on the results of this study, I would use mayo without hesitation when making chocolate chip cookies and I would be comfortable making the same substitution with other types of cookies. I would use mayo in a pinch in cakes that don’t call for mayo. I would expect the cake to be enjoyable (aren’t all cakes?!) but sub-par.

Did you enjoy Cupcake Project Substitution Lab? Let me know in the comments. I’m considering making it a regular feature and would love your input and suggestions for future tests.

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  1. Lee Kwiwasays:

    I just Love it..its so helpful.
    Thank you

  2. Valeriesays:

    Your mayo substitute worked fantastic for my cornbread, thank you! I think it even tasted better. Definitely more dense, but great flavor.

  3. April Ballsays:

    Mayonnaise is great in brownies. Especially if you like them more like fudge, than cake.

  4. Ranisays:

    DH is looking to sub mayo for both egg and oil with a box of brownie mix. The recipe calls for 2 eggs, 3/4 c. oil, and 1/4 c of water. So if we sub 6 tbsp of mayo for the egg, how much do you figure to reduce the oil? Maybe 1/3 cup?

  5. presa1200says:

    I think mayo work well in cookies because the dough is denser compared to cupcakes. Since common substitution for egg is oil and mayo already has it, that is why it works great. Thanks for your post and the lab thingy.

  6. Marysays:

    Ok, I am SO glad you did this! I tried it yesterday and it worked great! I’ve tried bananas before but the flavor always over powered the cookie, which wasn’t bad- I just didn’t want banana cookies. :) So, I was on the fence with the mayo and your blog helped me take the leap- so glad I did! The texture was slightly different- like, if I didn’t let the cookies cool completely they were crumbly, but still great texture and taste. Thanks again!!

  7. Izzysays:

    Thanks! Its snowing outside and we decided to make cookies, but we didn’t have any eggs! We will try the mayo and hopefully it tastes the same! Thank you!

  8. Rachaelsays:

    Thank you for running this experiment! I was doubtful of whether I should try substituting an egg for some mayo in my cookies, as most references to it don’t actually include whether the author has tried this themselves. I have new hope! The only question remaining is whether to exclude the salt from the recipe… I guess I’ll go find out. Great post! =)

  9. Alysays:

    Interesting that the mayo did so well with the cookies! I’ve made a chocolate mayo cake before (and loved it) but didn’t think to adapt it for other recipes.

  10. Claudia Msays:

    I had a hankering for cookies a few nights ago but didn’t have any eggs in the house. I ended up making Snickerdoodles, replacing the eggs and butter with the mayonnaise. I also discovered at the last minute that I didn’t have baking soda, so I substituted twice the amount of baking powder for the baking soda. They turned out to be amazing cookies…soft inside yet crisp on the outside. I may never go back to my old tried-and-true recipe.

  11. RBjsays:

    Cool bean! More please and thank you.

  12. Amysays:

    Please please please make this a regular feature! As an ex-chemist, I’m always interested in the science-y side of baking. :)

  13. Rebeccasays:

    I would really like more of that :) Nice Idea!
    Take care, rebecca

  14. Beth @ bethcakessays:

    I’ve never thought of replacing eggs with mayo, but I really love the whole idea of this Substitution Lab! Looking forward to seeing more of them! :)

  15. Erin @ The Spiffy Cookiesays:

    I wonder if Greek yogurt could be used? It’s not egg based but has a similar consistency

  16. Francescasays:

    It’s a great feature and a really interesting experiment. Thank you. I hope there will be more to follow like this post in the future :)

  17. Christinesays:

    Great feature! Please do more! Perhaps some non- wheat flours in sweets?

  18. Joanna Norlandsays:

    This is an excellent feature – espec for us working mums who are always running out of things! My current question: Can you substitute egg white for egg in muffins & cupcakes? I make a lot of custard, so I always have an overage of egg white in the freezer (thanks to your terrific post on freezing egg white in a silicon muffin tin)

  19. Efreet in the Ovensays:

    I find the mayo works as substitution for both eggs AND fat – if you still put extra oil/butter into your batter, you have too much grease going on, which might be why the cupcakes didn’t dome…

  20. Kaesha Rsays:

    Yes, substitutions are helpful. Please keep them coming.

  21. Rimasays:

    Oooo Super nice to know… Yea I would think that it would probably work on cookies. I think I gotta try it.

  22. Denisesays:

    Thanks for this information.
    Very helpful!

  23. Janice Hsays:

    I really like the idea of making this a regular feature of your blog! Although I usually have all the ingredients on hand for a baking recipe, I have definitely been in a situation where I discover I’m missing something when I’m already partway through the recipe. I have found that most substitutions are good, but never bake things side by side to be able to make the comparison. Other ideas? Cocoa+fat vs. baking chocolate; baking powder vs. baking soda+acidic liquid; Greek yogurt or sour cream vs. oil or butter…endless possibilities! Iris makes a good point about how difficult it can be to find things in other countries or sometimes even just small towns!

  24. Marysays:

    The other night I ran out of eggs while making dinner. I needed just one egg for my super soft, 40-min dinner rolls. I did the mayo substitute and the results were great. I actually think they turned out BETTER with the mayo. Happy discovery!

    • reesesays:

      im so glad i came across this i ran out of eggs i figured mayo would do but needed to make sure and needed to get ratio. thanx u guy/gals

  25. Irissays:

    I love the way you present your research. I was in academy and it was very fun to see a “paper” about cake like yours :)
    Thanks for sharing!
    My suggestion for substitution is about some stuff that you only have in US, and here in Brazil is impossible to find as buttermilk, sour cream, whipping cream, etc.

  26. HeartBaker25says:

    I absolutely LOVE this idea! I’d love if you did a feature on using oil v. butter in cupcakes. I was researching this a bit today and I have a batch of red velvet cupcakes in the oven right now where I used a combo of oil and butter. I had made a batch with butter and another batch with oil earlier in the week and wasn’t happy with either after they sat for two days. PLEASE make this experimenting idea a regular feature!

    • Stefsays:

      Thanks! I’ve actually done TONS of tests on that when I was working on Ultimate Vanilla and Ultimate Chocolate. I’ve always been happiest with a combo of the two. But, I love the idea of sharing my results in a Labs post!

    • Teresa Jamessays:

      Ok I will try I have three kids screaming cake I’m Out of eggs I’ve used mayo in place of oil before does make cake heavier but thats all however I do usually use applesauce in place of oil its awesome

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