This easy to make cake is plush and moist, thanks to the old-school vintage trick of using mayonnaise in the batter.

A slice of chocolate mayonnaise cake on a plate, with the remaining cake in a pan next to it.

I don’t talk much about my “other” day job, but I’m a freelance food writer that contributes to a number of outlets, including Serious Eats. Recently, due to a project that involved me making buckets of mayonnaise, I need to frantically use it up before it went bad. Of course, I went with numerous batches of deviled eggs, including my beet-dyed eggs devil eggs with za’atar and tahini, my chorizo deviled eggs, and my pimiento deviled eggs. But beyond making grilled cheese and coleslaw, I turned to a classic vintage recipe, the chocolate mayonnaise cake. Though it sounds weird, the recipe yielded a moist and decidedly tender and plush snacking cake that had my husband going back for seconds and thirds.

Chocolate mayonnaise snacking cake with sour cream frosting in a pan.

Why Mayonnaise and Which One to Use

The classic chocolate mayonnaise cake is a vintage recipe developed back in the 1950s when eggs were expensive. Some things don’t change right? Mayonnaise, if you’ve never made it from scratch, is an emulsion of eggs and oil. Both ingredients that you find in cakes and other baked goods. The emulsion of these two ingredients mean they blend in well with cakes, yielding a moist (from the oil) and tender (from the eggs) cake. The additional lofty plushness that in the cake probably came from the already mixed and emulsified oil in the eggs.

Typical mayonnaise also has a little salt and some vinegar or acid in it, with some mayonnaise brands adding in additional flavoring like garlic. I’d recommend avoiding any mayonnaise that uses garlic or other flavorings. But, to be honest, with the strong and sharp chocolate flavor that you get natural cocoa, you most likely won’t taste those mild flavorings (unless you have a very refined palate or are a supertaster). Use whatever mayonnaise you have on hand, including homemade, no need to buy a special jar of it just for this recipe.

That said, I have not tested this recipe with Miracle Whip or Vegannaise/Vegan mayo substitutes. The internet says both will work! But I personally haven’t tested it. If you do try it, please leave a comment below letting me know how they work out!

A slice of chocolate mayonnaise cake on a plate, with the remaining cake in a pan behind it.

Key Ingredients in Chocolate Mayonnaise Snacking Cake

Mayonnaise: As I said above, mayonnaise is an emulsion of egg and oil, making it an easy substitute for both.
Coffee: Coffee boosts the chocolate flavor. You can also just use instant coffee or just swap out hot water if you don’t have coffee.
Cocoa: I use natural cocoa powder but you can sub out Dutch-process. See my section below on how to do that.
All-purpose flour: This gives structure. I prefer all-purpose as the large amount of cocoa used in this recipe already reduces the gluten in it, keeping it tender.
White and brown sugar: Sweetens the cake, keeps it tender, and the molasses in the brown sugar lends deeper chocolate flavor and more moisture because the molasses is hygroscopic (attracts water).
Baking powder and soda: Both are leaveners, giving the cake loft and resulting in a plus crumb.
Vanilla: Boost and gives the chocolate dimension.
Sour cream (in the frosting): This give a slight tang and dimension to the frosting and makes it more smooth and spreadable at room temperature.

A slice of chocolate mayonnaise cake on a plate, with a piece of the cake on a fork. Next to the cake is a glass of milk.

How to make this cake

One of the favorite things about this cake recipe is that it’s super easy to make and only uses one bowl!

Start off with measuring fresh brewed coffee or hot water into a glass measuring cup. If using water, you can spike it with a bit of instant coffee or espresso powder but this is optional (the coffee flavor is there just to boost the flavor of the chocolate, you won’t taste it). Add the cocoa powder, stirring to dissolve the powder. “Blooming” the cocoa like this in the hot water also helps deepen and strengthen the chocolate flavor.

Left image is coffee in a glass measuring cup with natural cocoa in it. Right image is the cocoa whisked into the coffee, with a small whisk in the liquid.

Whisk together flour, white and brown sugar, baking powder, baking soda, and salt in a large bowl. Add to the dry ingredients the coffee chocolate liquid, mayonnaise, and vanilla to the bowl. Stir with a whisk until a smooth batter forms.

Left image is mayonnaise and vanilla in the bowl with dry ingredients, with the cocoa coffee mixture being poured into the bowl. right image is a spatula mixing the ingredients together.

Pour the batter into a buttered 9” x 13” x 2” pan and bake.

Left image is a hand brushing melted butter into a baking pan. Right image is the cake batter being poured into the pan.

Once the cake is made and cooled, you can either just dust it with a little powdered sugar to eat or top it with your favorite frosting. I included a quick chocolate frosting with this recipe that uses sour cream which gives it a nice tang and added dimension. To make this frosting melt dark chocolate and butter. Then sift and stir in powdered sugar. Mix in some sour cream, vanilla extract, and a touch of corn syrup (totally optional but I like to add it to give the frosting a little shine).

Left image is cake baked in a pan. Right image is a spoon spreading the chocolate frosting over the cooled cake.

What sort of cocoa powder should you use?

I developed this recipe using natural cocoa powder, which is naturally acidic. The sharper flavor of the natural cocoa cuts helps cut through some secondary flavors that might be present in mayonnaise (like garlic or lemon). But you can also use Dutch-processed cocoa as well if that’s all you have or if you prefer the more mellow and rich flavor of Dutch-processed. Just swap out the same amount of Dutch-processed cocoa for the natural cocoa (3/4 cup) and omit the baking soda in the recipe.

Keep in mind that if you swap the cocoa, the color of the cake will be darker and you will have a tighter crumb to the cake, which is not a bad thing! Just different.

Two spoonfuls of different cocoa powder on a marble surface, with darker Dutch-processed cocoa in front, and natural cocoa powder in back.

Storage

This cake stays moist for up to three or four days. I like to cover it tightly with plastic wrap or aluminum foil and store it in the fridge for optimum freshness. Take out from the fridge and let it come to room temperature before serving.

You can also freeze the cake, whole or in slices. If it’s whole and already frosted, cover the pan with plastic wrap, then aluminum foil and freeze as is. If it’s already sliced, I like to place the slices onto a baking sheet and then place that in the freezer for two to three hours, or until the cake is frozen solid. Then I’ll wrap each piece in plastic wrap or place it in a resealable freezer Ziploc bag for further storage. Cake can be stored in the freezer for two to three months. Just make sure to thoroughly thaw it before serving.

A slice of chocolate mayonnaise cake on a plate with a piece of cake on a fork. There is a glass of milk behind the plate.

If you like this chocolate recipe, check out some of these other chocolate recipes:

Print Pin

No ratings yet

Chocolate Mayonnaise Snacking Cake

This chocolate mayonnaise cake is a simple and easy recipe based on a vintage recipe using mayonnaise in place of eggs and butter/oil. The result is a moist and plush cake that comes together quickly in one bowl. I paired it with an easy-to-make chocolate sour cream frosting but you can just dust it with powdered sugar if you want something simpler.

Course coffee time, Dessert, Snack

Cuisine American

Keyword cake, chocolate, easy

Prep Time 25

Cook Time 25

Servings

Calories 899kcal

Author Irvin

Ingredients

Cake Batter

1 1/4 cup hot water 300 ml or 300 g (or fresh brewed coffee)
1 teaspoon instant coffee or espresso powder (optional but recommended, skip if using coffee instead of water)
3/4 cup natural cocoa powder 65 g (see section above for about cocoa powder and substituting Dutch-processed cocoa)
2 1/4 cups all-purpose flour 315 g
1 cup white granulated sugar 200 g
1/4 cup packed dark brown sugar 55 g
2 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon kosher salt
1 1/4 cups mayonnaise 300 g
2 teaspoons vanilla extract

For Pan

1 tablespoon butter melted

Frosting

6 1/4 ounces dark chocolate chopped (175 g)
6 tablespoons unsalted butter 85 g
2 1/2 cups confectioner’s sugar sifted, 290 g
1/2 cup sour cream 125 ml or 125g
1 tablespoon corn syrup optional, see note below
2 teaspoons vanilla extract

Instructions

Preheat the oven to 350°F.
Make the cake by measuring out the hot water (or fresh brewed coffee) into a 2-cup glass measuring cup or small bowl. Add the instant coffee or espresso powder and the cocoa powder to the liquid and stir to dissolve the cocoa powder.
Place the flour, white sugar, brown sugar, baking powder, baking soda, and salt into a large bowl. Whisk all the dry ingredients together.
Add the chocolate coffee liquid, mayonnaise, and vanilla to the bowl. Stir with a whisk breaking up any big clumps, until a smooth batter forms.
Brush the bottom and sides of a 9 x 13 x 2-inch pan with the melted butter.
Pour the batter into the pan, smoothing it out so you have an even layer.
Bake in the oven for 25 to 30 minutes, or the sides of the cake pull away from the pan a little bit, the top of the cake starts to crack slightly, and a toothpick inserted in the center of the cake comes out clean.
Let cool in the pan for two hours, or until it gets to room temperature before frosting.
Make the frosting by placing the dark chocolate and butter in a microwave-safe bowl. Melt the two together, cooking in 30 second intervals, stirring between each cooking cycle, until both chocolate and butter are melted and smooth.
Sift in the confectioner’s sugar (do not skip this test, as lump confectioner’s sugar does not dissolve, and you’ll end up with lumpy frosting). Add the sour cream, corn syrup (if using) and vanilla. Stir it all together with a balloon whisk until smooth.
Once the cake is cooled to room temperature, ice the top of the cake with the frosting.

Notes

The corn syrup in the frosting adds a sheen and gloss. You can substitute honey (though this will add a slight honey flavor to the frosting) or you can skip it all together, though the frosting will look less shiny.

Nutrition