This post is sponsored by Mirum, however all opinions are 100% my own.

Moist Chocolate Cake with a Secret Ingredient

It’s perfectly rich and chocolatey, its fluffy, it’s moist, it has just the right amount of sweetness — oh and that topping! This easy chocolate cake is all the things you look forward to in a slice of cake and then some! And there’s a secret ingredient that no on would suspect: mayonnaise! Apparently this was a super popular recipe back in the day, my mom told me how much everyone loved it. So I’m not sure why I hadn’t heard of it until recently. Better later than never though because I’m totally smitten with this chocolate mayo cake. Now pull out that mayonnaise and get baking! I know it may sound weird but it just works, this is such a dreamy cake and you’ll have everyone savoring every last bite! You can even add your own unique twist and try this cake with a chocolate fudge frosting or another frosting of choice. My whole family loved this cake and I’m sure it won’t be forgotten. I know my kids will be asking for this again and again. I mean, who wouldn’t love it? All good things start with chocolate!

My Favorite Mayonnaise Brand

For this chocolate mayonnaise cake recipe, I used my go-to mayonnaise – Best Food’s Mayonnaise (AKA Hellmann’s Mayonnaise). It’s rich and perfectly creamy and it’s a key ingredient in this moist chocolate cake. I always knew it was such a versatile ingredient but never thought to add it to cake! It just makes sense though when you check the ingredients label. I love that I can purchase Hellman’s Mayonnaise and other Unilever foods in bulk at Sam’s Club. And while I’m shopping at Sam’s Club I love to use their Scan and Go App. The Scan and Go App is just as it’s titled – it lets you scan the items while you shop and simplifies the whole checkout process. With this service, you can skip the checkout lines! Simply proceed to the exit where a costumer service member will be waiting to scan the barcode on your app (which shows all of your purchases) and off you go! I love it! Sam’s Club also offers Club Pick Up where you can shop from home (order the items you want online) then someone at Sam’s Club will do all the shopping for you and you just show up to pick up your items hassle free. Genius! It leaves you with more time to do the things you love! Or you can sign up for their subscription service to have the prodcuts you love shipped on a regular basis, a great way to stay on top of things!

Chocolate Mayonnaise Cake Ingredients

All-purpose flour Unsweetened cocoa powder Baking soda and baking powder Eggs Granulated sugar Vanilla Mayonnaise Warm water

Marshmallow Frosting Ingredients

Egg whites Granulated sugar Cream of tartar Vanilla extract

How to Make Chocolate Mayonnaise Cake

Preheat oven and spray baking dish. Whisk dry ingredients. In a separate bowl beat eggs sugar and vanilla 3 minutes, then blend in mayonnaise. Mix in flour alternating with water. Pour into prepared pan and bake until set. Let cool, then frost.

How to Make Marshmallow Frosting

Fill a large saucepan with about 1 1/2-inches of water and bring to a simmer. Add egg whites, granulated sugar and cream of tartar to a heat proof bowl of an electric stand mixer. Set bowl over saucepan and heat mixture, whisking constantly until it’s very warm, about 3 – 4 minutes. Remove from heat and transfer bowl to electric stand mixer fitted with a whisk attachment. Beat mixture beginning on low and increasing to high speed until stiff glossy peaks form, about 5 – 7 minutes. Mix in vanilla.

Can This Cake Be Made in Advance?

The chocolate mayo cake itself will stay moist for a few days, but the marshmallow frosting may lose some volume over time. If you live in a humid climate, the homemade marshmallow frosting will be tougher to whip up and won’t hold its shape for long so I recommend enjoying this cake day of.

Can I Use Butter Instead of Mayo?

No, there’s no oil substitute for the mayonnaise in this chocolate mayonnaise cake. Trust me, you won’t taste the mayo in this moist chocolate cake! It just makes the cake super rich and extra delicious.

How to Make Chocolate Shavings

The easiest way to make chocolate shavings is to run a vegetable peeler along the edge of a bar of chocolate. Be careful when doing this — you don’t want to break the chocolate bar by accident!

Tips for the Best Chocolate Cake and Marshmallow Frosting

If even the tiniest bit of egg yolk gets into the marshmallow frosting, it won’t whip up properly. So be really careful when separating the yolks from the whites. Be careful when heating the frosting ingredients over a pot of boiling water. You don’t want the bowl the frosting is in to touch the hot water, otherwise you may scramble the eggs by mistake. When measuring out the flour, use the spoon and level method for best results.

More Chocolate Cake Recipes You’ll Love:

German Chocolate Cake Flourless Chocolate Cake Molten Chocolate Lava Cakes Chocolate Zucchini Cake with Chocolate Cream Cheese Frosting Chocolate Sheet Cake Classic Chocolate Cake with Chocolate Buttercream Frosting

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