Chocolate Mayonnaise Sheet Cake

Bake a fluffy and light chocolate sheet cake that’s indulgent and incredibly tender, all thanks to a secret ingredient: mayonnaise! The decadent and velvety fudge buttercream frosting compliments the moist cake.

By
Annika Panikker
Annika Panikker
Annika Panikker
Annika is a chef turned food content creator since 2017, and is currently featured in Simply Recipes. She has been in the food service industry since 2010 and started out as home baker in Mumbai, India when she was 15 years old.
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Published January 11, 2023
Annika Panikker
Chocolate Mayonnaise Sheet Cake with a Slice Cut

Simply Recipes / Annika Panikker

My first memory of this cake takes me back to when I was younger at my aunt's house. We were playing “guess the ingredients in this recipe” and I remember losing, as I had no clue that mayonnaise could be added to chocolate cake. 

The beauty about this sheet cake, apart from the chocolate of course, is it’s a great make ahead dessert that comfortably feeds a crowd. You can bake it in a throw away aluminum container, making it travel friendly for picnics. I love making this recipe when I am invited over to a friend's house as it is not only polite to go with something, but also chocolate is a good ice breaker. 

Mayonnaise Cake History

Even though the addition of mayonnaise in cake sounds strange, it dates back before the Depression era, when resourceful bakers added mayonnaise to cakes instead of butter, eggs, and other dairy ingredients like milk or sour cream. It was later popularized by the mayonnaise company Best Foods in order to promote their product. It wasn’t only added in chocolate cake; there are other mayonnaise cake recipes with spices, nuts, and fruits. 

Chocolate Mayonnaise Sheet Cake in a Baking Pan, Surrounded by Small Plates, Utensils, and One Small Plate with a Slice of Cake

Simply Recipes / Annika Panikker

What Does Mayonnaise Add to Cakes?

Mayonnaise is made up of eggs, oil, and acid. When we add it to the batter it ensures a very soft and fluffy cake. Flavor-wise, you don’t taste the mayonnaise in the baked cake. 

Ideally, use a full-fat mayonnaise for the best results.  You can use low fat in this recipe, but it will affect the texture of the cake and make it a little chewy. I wouldn’t recommend using vegan mayonnaise in this recipe. 

The Best Cocoa Powder for This Recipe

This recipe calls for an unsweetened Dutch processed cocoa powder, as it gives an intense chocolate flavor to the cake. You could use any unsweetened cocoa powder you have on hand. I prefer Dutch processed as it is darker with a richness that feels more indulgent.

To Frost or Not to Frost?

The cake is satisfying on its own, but the addition of the frosting not only adds more flavor but texture as well. It is silky smooth and creamy which makes every bite scrumptious. Hence my recommendation is to frost. 

Baking Pan of Chocolate Mayonnaise Sheet Cake with Slices Cut

Simply Recipes / Annika Panikker

Sensational Sheet Cakes

Chocolate Mayonnaise Sheet Cake

Prep Time 20 mins
Cook Time 30 mins
Cooling Time 30 mins
Total Time 80 mins
Servings 12 servings
Yield 1 (9x13-inch) cake

Ingredients

For the cake

  • Butter, for greasing the pan

  • 2 cups (242g) all-purpose flour

  • 1 cup (120g) unsweetened Dutch processed cocoa powder 

  • 1 1/2 teaspoons baking powder

  • 1 1/2 teaspoons baking soda

  • 1/4 teaspoon salt

  • 3/4 cup (177ml) hot water

  • 2 tablespoons (30g) instant coffee powder or instant espresso powder

  • 2 large eggs

  • 1 cup (220g) sugar

  • 1/2 cup (100g) brown sugar, lightly packed

  • 1 cup (260g) mayonnaise

  • 1 tablespoon vanilla extract

For the frosting

  • 1/2 cup (80g) finely chopped semisweet or bittersweet chocolate 

  • 1/2 cup (113g) unsalted butter 

  • 2 tablespoons (30g) unsweetened Dutch processed cocoa powder 

  • 1 cup (130g) powdered sugar

  • 1/2 cup heavy cream

Special Equipment

  • 9x13-inch baking pan

Method

To make the cake
  1. Preheat the oven:

    Preheat the oven to 350°F (180°C). Brush a 9x13-inch sheet pan with a little butter and set aside.

  2. Mix the dry ingredients:

    In a medium bowl, stir together the all-purpose flour, cocoa powder, baking powder, baking soda and salt until evenly combined. Set aside.

    Dry Ingredients (All-Purpose Flour, Dutch Processed Cocoa Powder, etc) Mixed Together in a Bowl Using a Spatula for Chocolate Mayonnaise Sheet Cake Recipe

    Simply Recipes / Annika Panikker
  3. Mix wet ingredients:

    In a glass measuring cup, add the instant coffee to the hot water. Mix until dissolved and set aside.

    Espresso Powder Mixed with Hot Water in a Pyrex Cup for Chocolate Sheet Cake Recipe

    Simply Recipes / Annika Panikker
  4. Beat the mayonnaise and sugars:

    In a large mixing bowl, beat the mayonnaise and white and brown sugars using an electric beater just until pale and creamy.

  5. Add the eggs:

    Add the eggs one at a time and beat well. Make sure to scrape down the sides of the bowl with a spatula periodically to ensure everything is getting incorporated. Pour in the vanilla and beat to mix.

    Wet Ingredients Mixed Together in a Bowl for Chocolate Mayonnaise Sheet Cake Recipe

    Simply Recipes / Annika Panikker
  6. Fold the wet and dry ingredients together:

    Roughly divide the dry ingredients in thirds and add the first third to the egg mayonnaise mixture with half of the hot coffee. Beat until combined. Add the second part of the dry ingredients with the other half of the hot coffee and beat well. 

    Add the final third of the dry ingredients and give it a good mix. The batter should be neither stiff nor runny.

    Wet and Dry Ingredients Slowly Mixed Together in a Bowl for Sheet Cake Recipe

    Simply Recipes / Annika Panikker
    Chocolate Mayonnaise Sheet Cake Batter in a Bowl

    Simply Recipes / Annika Panikker
  7. Bake the cake:

    Pour the batter into the prepared tin and bake at 350°F (180°C) for 28-30 minutes or until a toothpick inserted into the center comes out with moist crumbs (not wet cake batter but sticky chocolate crumbs). Let the cake cool completely before frosting.

    Chocolate Mayonnaise Sheet Cake Batter Poured into a Baking Pan

    Simply Recipes / Annika Panikker
    Chocolate Mayonnaise Sheet Cake Batter in a 9x13 Baking Pan

    Simply Recipes / Annika Panikker
    Baked Chocolate Mayonnaise Sheet Cake in a Baking Pan

    Simply Recipes / Annika Panikker
    Clean Toothpick after Inserted into Chocolate Mayonnaise Sheet Cake

    Simply Recipes / Annika Panikker
To make the frosting
  1. Melt the chocolate:

    In a small microwaveable bowl, melt the dark chocolate in a microwave using 20-second intervals until smooth, stirring between each interval. (It should take 40-70 seconds total). Set the chocolate aside to cool.

    Bowl of Melted Chocolate for Chocolate Sheet Cake Recipe

    Simply Recipes / Annika Panikker
  2. Beat the butter and sugar:

    In a large bowl, use an electric mixer to beat the butter until it’s creamy and fluffy.

    Add the powdered sugar to the creamed butter. Starting on the lowest speed, beat the mixture together. As the sugar gets incorporated, increase the speed and beat the frosting for 2-3 minutes on high speed.

    Whipped Butter in a Bowl

    Simply Recipes / Annika Panikker
    Sugar Whipped with Butter in a Bowl for Chocolate Mayonnaise Sheet Cake

    Simply Recipes / Annika Panikker
  3. Add the cocoa powder:

    Add the cocoa powder to the frosting and beat well until combined. Make sure to scrape down the sides every now and then for a smooth frosting.

    Chocolate Powder Mixed into Buttered Sugar and Butter for Chocolate Mayonnaise Sheet Cake Recipe

    Simply Recipes / Annika Panikker
  4. Add the cream and cooled melted chocolate:

    Add the cream and melted dark chocolate to the frosting and beat well until combined. Let this set in the fridge for 10 minutes before frosting the cake. 

    Tip

    Make sure the melted chocolate has had a chance to cool slightly.

    Heavy Cream Added to the Bowl with the Chocolate Butter Mixture

    Simply Recipes / Annika Panikker
    Bowl of Chocolate Buttercream for Sheet Cake Recipe

    Simply Recipes / Annika Panikker
Assemble the cake
  1. Frost:

    Spread the frosting over the cooled cake and create a swirls using your spatula or the back of a spoon.

    Chocolate Buttercream Spooned onto Sheet Cake in the Baking Pan
    Back of a Spoon Used to Make Wispy Shapes on the Icing for Chocolate Mayonnaise Sheet Cake

    Simply Recipes / Annika Panikker
  2. Serve and store:

    Slice and serve the cake. 

    Once the cake is baked, leave it in the baking tin and cover it with plastic wrap. Leave it at room temperature for 1 day or refrigerate for up to 7 days. 

    Once the sheet cake is frosted you can store it in the fridge for 3 days, however when you are ready to eat, let the cake come to room temperature before slicing as the frosting will be hard.

    Did you love the recipe? Leave us stars below!

    Chocolate Mayonnaise Sheet Cake

    Simply Recipes / Annika Panikker
    Slice of Chocolate Mayonnaise Sheet Cake on a Plate with a Fork

    Simply Recipes / Annika Panikker
Nutrition Facts (per serving)
546 Calories
33g Fat
58g Carbs
5g Protein
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Nutrition Facts
Servings: 12
Amount per serving
Calories 546
% Daily Value*
Total Fat 33g 42%
Saturated Fat 13g 63%
Cholesterol 74mg 25%
Sodium 429mg 19%
Total Carbohydrate 58g 21%
Dietary Fiber 2g 6%
Total Sugars 38g
Protein 5g
Vitamin C 0mg 0%
Calcium 70mg 5%
Iron 3mg 16%
Potassium 206mg 4%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
Nutrition information is calculated using an ingredient database and should be considered an estimate. In cases where multiple ingredient alternatives are given, the first listed is calculated for nutrition. Garnishes and optional ingredients are not included.