Chocolate Mayonnaise Cake

I know. Mayonnaise in a cake doesn’t sound like something you plan to make...

The first time I saw it, I paused. Not because it looked complicated, just because it didn’t quite make sense.

But once you think about it, it does. Mayonnaise is actually just eggs and oil. Two things that already belong in a cake. So I tried it, mostly out of curiosity!

And what comes out of the oven is exactly what you want from a chocolate cake: soft, rich, and surprisingly light, without feeling heavy or overly sweet.

Jorge didn’t know what was in it at first. He just had a slice, said it was good, and went back for another.

Then I told him. He paused… looked at the cake… and had another slice anyway!

Between you and me, this Chocolate Mayonnaise Cake reminds me a bit of the first time I made my 3-Ingredient Ice Cream Bread. Same hesitation… same surprisingly good result.

Ingredients for Chocolate Mayonnaise Cake

If you’re unsure about the mayonnaise… that’s normal. It’s not the kind of ingredient you expect in a cake, and it feels a bit wrong the first time.

But once you see how it comes together, and more importantly, once you taste it, it stops being a question. It just becomes a really good chocolate cake.

Here are all the ingredients you need to make this cake:

For the Cake:

• 1½ cups all-purpose flour (190g) – The base. Nothing fancy, just what holds everything together.
• 2 teaspoons baking powder – Keeps the cake light and gives it that soft rise.
• ½ cup granulated sugar (90g) – Enough to sweeten without overpowering the chocolate.
• ½ cup unsweetened cocoa powder (40g) – This is where the depth comes from. Go for a good one if you can.
• ½ cup mayonnaise (140g) – This is the whole point. It replaces the eggs and oil, and gives you a really soft, moist crumb without extra effort.
• ¾ cup water (180ml) – Keeps the batter light and easy to bring together.
• 1 teaspoon vanilla extract – Rounds everything out.

To Serve:

• ¾ cup cold heavy cream (200ml) – Whips up light and balances the richness of the cake.
• 2 tablespoons cocoa powder (20g) – Keeps the topping in the same chocolate tone.
• 2 tablespoons powdered sugar (20g) – Just enough sweetness for the cream.

As you can see, it’s simpler than it sounds.

The mayonnaise replaces both the fat and the eggs, so you get a soft, moist cake without needing to measure multiple ingredients.

And once it’s baked, you don’t taste it. You just get a really good chocolate cake, enough for about 6–8 slices, depending on how generous you are.

If you’re leaning more towards something rich and dense, that’s definitely more Jorge's Fudgy Cheesecake Brownies.

How To Make This Chocolate Mayonnaise Cake

I start by turning the oven on to 350°F (180°C), mostly so I don’t have to think about it later.

Then I mix the dry ingredients in a bowl: flour, cocoa, baking powder, and sugar. It looks like any other cake at this point.

The mayonnaise goes in next, and this is usually where it feels a bit questionable. It’s thick, it doesn’t look like a batter yet, more like something that went slightly wrong.

But give it a second.

As I start mixing, it begins to come together. Slowly...

Then the water and vanilla go in, and that’s when it changes completely. It loosens up, smooths out, and suddenly looks exactly like what it’s supposed to be.

Into the pan it goes, nothing precise, just smooth the top, and into the oven.

And then you wait...

The smell comes first, proper chocolate cake, nothing unusual about it. No hint of what’s actually in there.

Once it’s baked, I let it cool completely. It’s soft, a bit delicate, so it’s better to leave it alone for a bit!

While it cools, I whip the cream. Cold cream, quick whip, then cocoa and sugar in at the end. Nothing complicated.

Then it’s just putting it together, spreading the cream on top or serving it on the side, depending on the mood.

The One Ingredient That Makes the Difference

You might answer the mayonnaise. But that’s the surprise, not the secret.

The real difference here is the cocoa powder. That’s what you taste in the end. That’s what gives the cake its depth, its richness, that proper chocolate flavor that actually stays with you.

The mayonnaise takes care of the texture; it keeps the cake soft, moist, and easy to get right. But the cocoa is what carries it.

That’s the one thing you don’t compromise. Use a really good one.

If you’re not sure which one to choose, a few things help when you’re at the store looking at the different options:

• Go for unsweetened cocoa powder: sounds obvious, but it matters
• Look for Dutch-processed (or “alkalized”): usually smoother, darker, and more balanced
• Check the ingredient list: it should just say cocoa, nothing else
• Avoid the cheapest option: this is one of those ingredients where you actually taste the difference
•  Stick to brands you’ve heard of or seen used often: they tend to be more consistent