This Old-Fashioned Chocolate Mayonnaise Cake is a classic, incredibly moist chocolate cake made with a surprisingly simple secret ingredient: mayonnaise. Don’t worry—the finished cake does not taste like mayonnaise. Instead, the mayonnaise adds richness, tenderness, and moisture, giving the cake a soft texture that stays delicious for days.

It’s an excellent old-fashioned dessert for birthdays, family gatherings, potlucks, holidays, or whenever you’re craving a rich homemade chocolate cake.

Prep Time

Prep: 15 minutes
Bake: 30–35 minutes
Cooling: 30–45 minutes
Total: About 1 hour 20 minutes
Servings: 12 slices

Equipment

9 × 13-inch baking pan
Mixing bowls
Whisk
Electric mixer or wooden spoon
Measuring cups and spoons
Rubber spatula
Wire cooling rack

Ingredients

For the Chocolate Cake

2 cups all-purpose flour
1 cup granulated sugar
¾ cup unsweetened cocoa powder
2 teaspoons baking soda
½ teaspoon salt
1 cup mayonnaise
1 cup water
2 large eggs
1 teaspoon vanilla extract
½ cup brewed coffee, cooled slightly

For the Chocolate Frosting

½ cup unsalted butter, softened
3 cups powdered sugar
½ cup unsweetened cocoa powder
1 teaspoon vanilla extract
3–5 tablespoons milk
Pinch of salt

Why Does Mayonnaise Work in Chocolate Cake?

Mayonnaise is primarily made from eggs and oil, two ingredients commonly used in traditional cake recipes.

The oil helps create a moist and tender crumb, while the eggs contribute richness and structure. Because mayonnaise already contains both, it works beautifully in chocolate cake.

The cocoa and vanilla provide the dominant flavor, so the finished cake tastes like a rich chocolate dessert—not mayonnaise.

Ingredient Notes

Mayonnaise: Use regular full-fat mayonnaise for the best texture. Avoid flavored mayonnaise or varieties with strong seasonings.

Cocoa powder: Unsweetened cocoa powder gives the cake its deep chocolate flavor. Natural cocoa powder works especially well with baking soda.

Coffee: Coffee intensifies chocolate flavor without making the cake taste strongly like coffee. You can replace it with additional water if preferred.

Eggs: Allow the eggs to come close to room temperature before mixing for a smoother batter.

Vanilla: Even a small amount makes the chocolate flavor taste richer and more rounded.

How to Make Old-Fashioned Chocolate Mayonnaise Cake

Step 1: Prepare the Oven and Pan

Preheat your oven to 350°F (175°C).

Grease a 9 × 13-inch baking pan thoroughly. You can also lightly dust it with flour or line the bottom with parchment paper.

Set the pan aside while you prepare the batter.

Step 2: Combine the Dry Ingredients

In a large mixing bowl, whisk together:

Flour
Sugar
Cocoa powder
Baking soda
Salt

Whisk until the cocoa is evenly distributed and there are no large lumps.

Step 3: Add the Wet Ingredients

Add the mayonnaise, eggs, vanilla, water, and cooled coffee to the dry ingredients.

Mix until the batter is smooth and everything is incorporated.

Be careful not to overmix. Once you no longer see dry flour, stop mixing.

The batter will be relatively thin. That is normal.

Step 4: Pour Into the Pan

Pour the chocolate batter into the prepared baking pan.

Use a spatula to gently spread the batter into an even layer, especially if the corners aren’t filling evenly.

Step 5: Bake

Place the cake in the preheated oven and bake for approximately 30–35 minutes.

Begin checking around the 30-minute mark.

The cake is ready when:

The center looks set.
A toothpick inserted into the center comes out with a few moist crumbs.
The cake gently springs back when lightly touched.

Try not to overbake it. Overbaking can take away the soft, moist texture that makes mayonnaise cake special.

Step 6: Cool Completely

Remove the cake from the oven and place the pan on a wire rack.

Allow it to cool completely before frosting.

If you frost the cake while it is still hot, the frosting can melt and slide across the surface.

Homemade Chocolate Frosting

While the cake cools, prepare the frosting.

Step 1

Beat the softened butter until smooth and creamy.

Step 2

Add the powdered sugar and cocoa powder gradually.

Mix on low speed initially so the dry ingredients don’t fly everywhere.

Step 3

Add vanilla and a pinch of salt.

Gradually add milk, one tablespoon at a time, until the frosting reaches a smooth, spreadable consistency.

Step 4

Beat the frosting for another 1–2 minutes until light and creamy.

Spread it evenly over the completely cooled cake.

Nutrition Facts

Approximate values per slice, assuming the cake is divided into 12 servings and includes frosting:

Calories: 430–470
Carbohydrates: 65–70g
Protein: 5–6g
Fat: 18–21g
Saturated Fat: 6–8g
Sugar: 45–50g
Sodium: 400–500mg

Nutrition information is an estimate and will vary depending on the specific brands and portion sizes used.

Tips for the Best Chocolate Mayonnaise Cake

1. Don’t use reduced-fat mayonnaise if you can avoid it

Full-fat mayonnaise provides the richness and moisture that make this cake especially tender.

2. Don’t overmix

Mix the batter just until the ingredients are combined. Excessive mixing can make the finished cake less tender.

3. Don’t overbake

This is one of the most important tips. Start checking the cake around 30 minutes.

4. Use coffee for deeper chocolate flavor

Coffee is an old-fashioned baking trick for making chocolate taste more intense.

5. Cool before frosting

A completely cooled cake gives you a much cleaner frosting layer.

6. Let it rest

The chocolate flavor becomes even better after the cake sits for several hours.

Delicious Variations

Chocolate Mayonnaise Cupcakes

Pour the batter into lined muffin cups and bake for approximately 18–22 minutes, checking with a toothpick.

Chocolate Peanut Butter Cake

Spread a thin layer of creamy peanut butter over the cooled cake before adding chocolate frosting.

Chocolate Ganache Topping

Instead of buttercream, pour a simple chocolate ganache over the cooled cake and allow it to set.

Cherry Chocolate Cake

Fold well-drained chopped maraschino cherries into the batter for a chocolate-cherry variation.

Extra Chocolate Version

Add a handful of semi-sweet chocolate chips to the batter before baking.

Simple Dusting

For a less rich dessert, skip the frosting and dust the cooled cake lightly with powdered sugar.

How to Store It

Store the frosted cake in an airtight container at room temperature for up to 2 days, provided the frosting and conditions are suitable for room-temperature storage.

For longer storage, refrigerate it in a tightly covered container for up to about 5 days.

Allow refrigerated slices to sit at room temperature for a short time before serving so the cake can soften again.

You can also freeze unfrosted cake portions. Wrap them tightly and freeze for up to 2–3 months. Thaw completely before frosting.

Frequently Asked Questions

Does chocolate mayonnaise cake taste like mayonnaise?

No. When properly prepared, the mayonnaise flavor isn’t noticeable. It primarily contributes fat and eggs, creating a moist, tender cake.

Can I use Miracle Whip?

It is possible, but regular mayonnaise is preferable because Miracle Whip has a sweeter and more distinctive flavor.

Can I leave out the coffee?

Yes. Replace the coffee with an equal amount of water. However, coffee helps enhance the chocolate flavor.

Can I make this cake ahead of time?

Absolutely. In fact, making it several hours ahead can make the texture even better. Keep it properly covered until serving.

Why is my cake dry?

The most common causes are overbaking, inaccurate flour measurement, or using too little mayonnaise. Measure flour carefully and start checking the cake early.

Can I use a different pan?

Yes, but baking time will change depending on the size and depth of the pan. A deeper or smaller pan will generally require more baking time, while cupcakes and thinner cakes require less.

Final Thoughts

This Old-Fashioned Chocolate Mayonnaise Cake is proof that some of the best desserts come from the simplest ingredients. The mayonnaise gives the cake an exceptionally soft and moist texture, while cocoa, vanilla, and coffee create a deep chocolate flavor.