Equipment
Ingredients
Dry Ingredients
- 250 g all-purpose flour
- 200 g granulated sugar
- 65 g dutch-processed cocoa powder
- 6 g baking soda
- 2 g baking powder
- 3 g salt
Wet Ingredients
- 225 g full-fat mayonnaise, room temperature
- 240 ml hot water
- 10 ml vanilla extract
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 423 kcal
- Protein
- 5 g
- Carbohydrates
- 54 g
- Fat
- 22 g
- Fiber
- 3 g
- Sugar
- 26 g
- Sodium
- 559 mg
- Saturated Fat
- 4 g
- Trans Fat
- 0 g
- Monounsaturated Fat
- 5 g
- Polyunsaturated Fat
- 13 g
- Cholesterol
- 12 mg
- Potassium
- 246 mg
- Calcium
- 32 mg
- Iron
- 1.7 mg
- Magnesium
- 46 mg
- Phosphorus
- 104 mg
- Zinc
- 0.8 mg
- Vitamin A
- 5 mcg
- Vitamin D
- 0.1 mcg
- Vitamin E
- 0.9 mg
- Vitamin K
- 46 mcg
- Vitamin B6
- 0.0 mg
- Vitamin B12
- 0.0 mcg
- Thiamin
- 0.05 mg
- Riboflavin
- 0.06 mg
- Niacin
- 0.6 mg
- Folate
- 12 mcg
- Water
- 41 g
- Alcohol
- 0 g
- Caffeine
- 6 mg
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat the oven to 175 degrees Celsius (350 degrees Fahrenheit) and generously grease a 23cm round cake pan.
Sift the all-purpose flour, granulated sugar, cocoa powder, baking soda, baking powder, and salt together into a large mixing bowl.
Whisk the mayonnaise and vanilla extract into the dry ingredients until the mixture resembles coarse, dark crumbs.
Stir the hot water gradually into the crumbly batter, whisking gently until the liquid is fully incorporated and the batter is smooth.
Bake in the preheated oven at 175 degrees Celsius (350 degrees Fahrenheit) for 35 minutes.
Cool the cake in the pan for 15 minutes before carefully turning it out onto a wire rack to cool completely.
Chef's Notes
- Full-fat mayonnaise is non-negotiable here; it acts as an already-emulsified combination of oil and egg yolks, providing unparalleled moisture to the crumb.
- Swapping the hot water for hot brewed coffee will not make the cake taste like coffee, but will significantly amplify the depth and richness of the chocolate flavor.
- Because the mayonnaise replaces butter, this cake remains exceptionally soft even when stored cold in the refrigerator.
- Do not overmix once the hot water is added. Stirring just until the batter is smooth prevents gluten development, keeping the texture tender.
Storage
Refrigerator: 5 days — Store in an airtight container to retain moisture.
Freezer: 3 months — Wrap the un-iced cake tightly in plastic wrap, then foil.
Troubleshooting
Cake is extremely dense or gummy
Cause: Using low-fat or fat-free mayonnaise, which lacks the essential oil content required to replicate the fat from eggs and butter.
Fix: Cannot be fixed
Prevention: Always use full-fat, traditional mayonnaise for baking applications.
Cake crumbles and falls apart when turned out of the pan
Cause: The cake was turned out too hot, or the pan was not adequately greased.
Fix: Repurpose the crumbled cake into a trifle or cake pops.
Prevention: Ensure the pan is well greased and optionally lined with parchment paper. Always allow the mandated 15 minute resting period before inverting.
Cultural Context
Originating during the rationing eras of the Great Depression and World War II, this cake is a quintessential example of American culinary ingenuity. By utilizing commercially emulsified mayonnaise, home bakers could bypass the need for expensive or scarce whole eggs, butter, and milk, while still achieving a remarkably decadent, moist dessert. The recipe saw a massive resurgence in the mid-20th century when mayonnaise companies printed it directly on their jar labels.
