Chocolate Mayo Loaf Cake

Chocolate mayonnaise cake sounds like one of those internet shock recipes invented for clicks, but it’s actually been around since the 1930s, born of Depression-era kitchens that needed a way to bake rich cakes without expensive eggs and butter. Mayonnaise is, after all, just oil and egg yolks emulsified with vinegar, which is exactly what a cake batter needs for tender moisture and structure.

The recipe couldn’t be simpler. Dry ingredients into a bowl, add water and vanilla, then beat in the mayo until smooth. No creaming butter, no separating eggs, no fussy steps. The result is a cake with a fudgy, almost brownie-dense crumb that stays moist for days, with deeper chocolate flavor than most cakes that try harder.

A dusting of confectioners sugar is all the finish this cake needs, but it also takes well to a simple ganache or cream cheese frosting if you want to dress it up.

Pro Tips

• Use full-fat real mayonnaise, not light or salad dressing. The oil ratio matters and substitutes throw off the moisture and texture.
• Sift the cocoa powder before adding it to the dry ingredients. Cocoa clumps and unsifted lumps can stay in the batter even with vigorous beating.
• Don’t tell anyone what’s in the cake until they’ve tried it. Skeptics convert fast on the first bite.
• For a deeper, more complex chocolate flavor, swap a tablespoon of the cocoa for instant espresso powder.

Variations

• Add a teaspoon of cinnamon and a pinch of cayenne for a Mexican-style chocolate twist.
• Stir a half cup of mini chocolate chips into the batter for melted pockets throughout.
• Bake the batter as cupcakes (about 22 to 24 minutes) for portable lunchbox treats.