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The Secret to Moist Chocolate Cake? Mayonnaise.

It might sound like the last thing you want in your baked goods, but the science of using mayo checks out.
By Published Dec. 20, 2021

The first time I heard of putting mayonnaise in a cake, I was shocked.

A condiment? In a baked good? But the first time I actually tasted a cake with mayonnaise, in the recipe for Easy Chocolate Snack Cake from The Complete Baking Book for Young Chefs, I was even more shocked.

The results don’t lie: Mayonnaise makes this chocolate snack cake perfectly moist. It turns out that there’s a good explanation for that.

Mayonnaise is primarily an emulsion of egg yolks and oil, both of which are common ingredients in cake, plus a bit of acid such as vinegar or lemon juice. It also contains an emulsifier called lecithin, which helps the oil coat the flour’s protein particles. All this means that adding mayonnaise to the cake batter boosts the moisture of the final product—and leaves none of its characteristic taste.

Testing showed that using oil or butter instead of mayo made for a drier cake, but keeping the eggs in addition to the mayonnaise improved richness and springiness. After trying this recipe you may never think of mayo as just a mere condiment again!

The Complete Baking Book for Young Chefs

Think baking fun starts and ends with cupcakes? Think again! From breakfast to breads and cookies to cakes (yes, even cupcakes!), kids can learn to bake it all with the help of this cookbook.  
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Easy Chocolate Snack Cake

Serves 12

  1. In medium bowl, whisk together 1½ cups all-purpose flour, 1 cup sugar, ½ teaspoon baking soda, and ¼ teaspoon salt. In large bowl, combine ½ cup Dutch-processed cocoa powder and ⅓ cup chocolate chips.
  2. Heat 1 cup water in microwave until hot and steaming, 1 to 2 minutes. Pour over chocolate mixture and whisk until smooth. Let cool for 10 minutes.
  3. Add ⅔ cup mayonnaise, 1 large egg, and 2 teaspoons vanilla extract to chocolate mixture and whisk until combined. Stir in flour mixture until just combined and no dry flour remains.
  4. Spread batter evenly into parchment paper–lined 8-inch square metal baking pan and bake at 350 degrees until toothpick inserted in center comes out clean, 34 to 38 minutes. Place pan on cooling rack and let cool completely, about 2 hours. Remove cake from pan, discard parchment, dust cake with confectioners’ sugar (if desired), and serve.


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