Time to get crazy.
Craving cake and don’t have time to run to the store? Wacky cake is coming to save the day. Made with basic pantry ingredients, this one-bowl wonder is so light and fluffy you’d never guess it was completely vegan.
Wacky cake is a traditional depression-era recipe. Also known as “crazy cake,” it’s remarkable for the fluffy crumb and rich flavor it achieves without any dairy or eggs. Cocoa powder provides rich flavor and oil tenderizes the crumb, while a magical duo of baking soda and vinegar raise it to fluffy perfection. While the classic wacky cake is simply flavored with cocoa, I’ve spiced it up with cinnamon and cayenne for a Mexican hot chocolate twist.
Adding a fiery spice like cayenne to a sweet bake can be tricky, since everyone has different heat tolerances. In testing, I found that ½ teaspoon cayenne was the perfect amount of heat for me—and tasters seemed to agree—but to be safe, I recommend adding half that amount to the batter at first, tasting, and adding more as you like. Remember, you can always add, but once that spice goes in, you can’t take it out.
This cake is leavened solely by the reaction between the baking soda and the vinegar, and this reaction begins as soon as the vinegar goes into the batter. This means it’s critical to get the cake in the oven as soon as possible once the vinegar is mixed in. Many older versions of this recipe emphasize this by directing people to mix the water, oil, and vinegar into the dry ingredients in the cake pan; and while I found this to be too messy and cumbersome to be practical, I understand the intent behind it. In testing, I found mixing in the bowl to work just fine, provided that the batter goes immediately into the tin and straight into the oven after that.
In the spirit of a hot chocolate, I’m topping this cake with a light whipped cream stabilized with a little powdered sugar and marshmallow fluff. The marshmallow fluff is optional, but if you leave it out I recommend topping the cake just before serving it, since the whipped cream won’t keep well if it’s not been stabilized.
This cake will keep for 3-5 days in an airtight container in the refrigerator. Because it’s an oil-based cake, its texture is still amazingly moist when served cold- but you can also let it come back to room temp before enjoying.
Enjoy!
Mexican Hot Chocolate Wacky Cake
(Serves 9)
Cake:
1 ½ cup (180 g.) all-purpose flour
1 cup (200 g.) granulated sugar
6 tbsp. (28 g.) cocoa powder
1 tsp. espresso powder
1 tsp. baking soda
¾ tsp. ground cinnamon
½ tsp. cayenne powder, plus more for topping (optional)
½ tsp. kosher salt
1 cup water
1/3 cup neutral oil
1 tbsp. white vinegar
Equipment: parchment paper, 8"x8" pan, hand-held electric mixer
Instructions
Preheat oven to 350 degrees, rack in the middle position. Grease and line an 8”x8” baking pan with parchment paper, allowing parchment to hang over the sides for easy removal.
In a large bowl, whisk together flour, granulated sugar, cocoa powder, baking soda, espresso powder, cinnamon, salt, and 1/4 teaspoon cayenne. Make a well in the center of the dry mixture and add water and oil. Whisk until completely combined. At this point, taste batter. If it’s spiced to your liking, continue with the next step. If not, add remaining 1/4 teaspoon cayenne and stir until incorporated.
Add vinegar and whisk just until incorporated, then immediately pour batter into prepared baking pan and transfer to oven. Bake until starting to pull away from the pan and a skewer under into the center comes out clean, 24-27 minutes. Let cool completely.
Frosting:
1 cup heavy cream
2 tbsp. confectioners’ sugar
1 tbsp. marshmallow fluff
Instructions
In a large bowl, using a handheld electric mixer, whisk heavy cream and confectioners’ sugar on low until slightly thickened, about 1 minute. Increase speed to medium and whisk until peaks start to form, about 2 minutes more. Shut off mixer.
In a small, microwave-safe bowl, microwave marshmallow fluff for 5 seconds. Stir; fluff should be slightly warm but not hot and loose enough to stir. If the fluff is still tight, microwave 5 seconds more.
Add marshmallow fluff to the center of the lightly whipped cream and continue to beat cream until soft peaks form and fluff is incorporated, about 1-2 minutes more.
Frost cooled cake with whipped cream frosting. Sprinkle with cayenne as desired.
Originally posted March 2, 2025.
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