In this article
Chocolate mayonnaise cake is the most famous wrong-sounding cake in America. It comes from the years when eggs and oil were hard to come by, and some practical cook worked out that a jar of mayonnaise is nothing but eggs and oil, already beaten together, with a little vinegar. So there are no eggs in this batter and no butter. The mayonnaise does both jobs.
For decades it was the cake many mothers made and did not explain. The jar went back into the refrigerator before company came, the cake went on the table, and everybody said it was the best chocolate cake in the county. They were right. The oil makes a crumb that is very soft and almost damp, the vinegar wakes up the baking soda and deepens the cocoa, and the cake stays moist for four days.
You cannot taste the mayonnaise, not even a little. The cake itself is the old recipe, unchanged. The frosting below is a simple cocoa one that takes five minutes, but use whichever chocolate frosting is yours.
Why this chocolate mayonnaise cake works
- Mayonnaise replaces the eggs and the fat. It is an emulsion of egg yolk and oil, so it blends in smoothly and coats the flour, which keeps the crumb tender.
- Vinegar and baking soda. The little bit of acid in the mayonnaise reacts with the 2 teaspoons of baking soda for a good rise, and it sharpens the chocolate.
- Oil, not butter. Cakes made with oil stay soft at room temperature. That is why this one is as good on day four as on day one.
- One bowl. Dry ingredients, then mayonnaise, cold water and vanilla, beaten smooth. No creaming, no separating, nothing to go wrong.
Ingredients
Makes one 9 by 13 inch cake, 15 squares. The measurements are in US cups with grams in brackets.
For the cake
- 2 cups all-purpose flour (250g)
- 1 cup granulated sugar (200g)
- 4 tablespoons unsweetened cocoa powder (25g)
- 2 teaspoons baking soda
- 1 cup real, full-fat mayonnaise (225g)
- 1 cup cold water (240ml)
- 1 teaspoon vanilla extract
- Butter or oil for greasing the pan
For a simple chocolate frosting
- 6 tablespoons butter (85g), soft
- 2 1/2 cups powdered sugar (300g)
- 1/2 cup unsweetened cocoa powder (50g)
- 4 to 5 tablespoons milk
- 1 teaspoon vanilla extract
- A pinch of salt
Use real, full-fat mayonnaise. Not the sweet salad dressing kind, which has extra sugar and spices, and not light or fat-free mayonnaise, which is mostly water and starch and bakes into a rubbery cake.
How to make chocolate mayonnaise cake
The cake
- Heat the oven to 350°F (175°C). Grease a 9 by 13 inch baking pan well, bottom and sides.
- In a large bowl, stir together the flour, sugar, cocoa and baking soda with a whisk until the color is even and no lumps of cocoa or soda remain.
- Add the mayonnaise, the cold water and the vanilla. Beat until smooth, about 2 minutes with a whisk or 1 minute with a hand mixer. The batter will be glossy and fairly thin. That is the whole batter.
- Pour the batter into the greased pan and spread it into the corners. Bake for 30 minutes, until the top springs back when pressed lightly and a toothpick in the center comes out clean or with a few moist crumbs.
- Set the pan on a rack and let the cake cool completely in the pan, about 1 hour. Frosting a warm cake melts the frosting and tears the soft top.
The frosting
- Beat the soft butter in a bowl until creamy. Add the powdered sugar, the cocoa, 4 tablespoons of the milk, the vanilla and the salt, starting the mixer on low. Beat for 2 minutes, until smooth and glossy, adding the last tablespoon of milk only if it is too stiff to spread.
- Spread the frosting over the cool cake right in the pan, swirling it with the back of a spoon. Cut into 15 squares.
Tips that make the difference
- Measure the cocoa level, not heaped. The cake looks lighter in the bowl than it bakes, and it darkens again by the next day.
- Do not overbake it. Start checking at 28 minutes. Five extra minutes are the only way to make this cake dry.
- A glass 9 by 13 dish bakes a little slower than metal. Give it 3 to 5 extra minutes and check with a toothpick.
- Bring the mayonnaise out of the refrigerator 20 minutes ahead. It whisks in more easily when it is not ice cold.
Variations
- Cold coffee. Use 1 cup of cold brewed coffee instead of the cold water. The chocolate gets even deeper and nobody tastes the coffee. This cake keeps every secret you give it.
- Layer cake. Divide the batter between two greased and floured 8-inch round pans and bake for 25 minutes. Double the frosting.
- Cupcakes. Fill 18 lined muffin cups two-thirds full and bake for 18 to 20 minutes.
- Chocolate chip. Scatter 1 cup of semisweet chocolate chips over the batter in the pan before baking.
Storage and make-ahead
Cover the pan with its lid or with foil and keep the cake at room temperature for up to 4 days. It stays soft and moist the whole time, and the flavor is best on the second day.
To freeze, wrap the unfrosted cooled cake or individual frosted squares in plastic wrap and then foil. It keeps for 3 months. Thaw at room temperature, still wrapped, for 2 to 3 hours.
It is a good cake to make the night before a potluck or a family reunion. Bake and frost it in the same 9 by 13 pan, cover it, and carry it just as it is.
Frequently asked questions
Can you taste the mayonnaise in chocolate mayonnaise cake?
No. Once it is baked, the mayonnaise disappears completely. It is only egg, oil and a little vinegar, the same things found in most chocolate cake recipes. Nobody guesses the ingredient unless they are told.
Can I use light mayonnaise or salad dressing?
No. Light and fat-free mayonnaise replace the oil with water and starch, and the cake turns out gummy. The sweet salad dressing kind adds sugar and spices that show up in the flavor.
Why are there no eggs in this cake?
The mayonnaise already contains them. A cup of mayonnaise brings enough egg yolk to bind the batter and enough oil to replace the butter. That is how the recipe got through the years when fresh eggs were scarce.
What frosting goes best on chocolate mayonnaise cake?
A simple cocoa and powdered sugar frosting like the one here is the classic. A cooked fudge icing or even a dusting of powdered sugar works too.
Bake it, frost it, put it on the table and say nothing. When somebody asks for the recipe, and somebody will, you can decide then whether the jar gets mentioned.
Chocolate Mayonnaise Cake (No Eggs, No Butter, One Bowl)
The old-fashioned chocolate mayonnaise cake: one bowl, no eggs and no butter in the batter, a cup of real mayonnaise and a cup of cold water, baked in a 9 by 13 pan and finished with a simple chocolate frosting. Dark, soft and moist for four days.
Ingredients
- 2 cups all-purpose flour
- 1 cup granulated sugar
- 4 tablespoons unsweetened cocoa powder
- 2 teaspoons baking soda
- 1 cup real, full-fat mayonnaise
- 1 cup cold water
- 1 teaspoon vanilla extract
- Butter or oil for greasing the pan
- 6 tablespoons butter (85g), soft
- 2 1/2 cups powdered sugar
- 1/2 cup unsweetened cocoa powder
- 4 to 5 tablespoons milk
- 1 teaspoon vanilla extract
- A pinch of salt
Instructions
- Heat the oven to 350°F (175°C). Grease a 9 by 13 inch baking pan well, bottom and sides.
- In a large bowl, stir together the flour, sugar, cocoa and baking soda with a whisk until the color is even and no lumps of cocoa or soda remain.
- Add the mayonnaise, the cold water and the vanilla. Beat until smooth, about 2 minutes with a whisk or 1 minute with a hand mixer. The batter will be glossy and fairly thin. That is the whole batter.
- Pour the batter into the greased pan and spread it into the corners. Bake for 30 minutes, until the top springs back when pressed lightly and a toothpick in the center comes out clean or with a few moist crumbs.
- Set the pan on a rack and let the cake cool completely in the pan, about 1 hour. Frosting a warm cake melts the frosting and tears the soft top.
- Beat the soft butter in a bowl until creamy. Add the powdered sugar, the cocoa, 4 tablespoons of the milk, the vanilla and the salt, starting the mixer on low. Beat for 2 minutes, until smooth and glossy, adding the last tablespoon of milk only if it is too stiff to spread.
- Spread the frosting over the cool cake right in the pan, swirling it with the back of a spoon. Cut into 15 squares.
