I followed the instructions nearly to a T, swallowing my doubt as I blended the mayonnaise in with the short list of ingredients. A foodie friend who knew what I was up to expressed her concern on twitter: "mayo?? i am a little bit worried. but let me know how it goes." I was worried as well, but I threw it in the oven and headed back to the couch to wait.
Result? Perfection! It sounds impossible, I know but this cake is moist, rich, chocolatey, and fluffy--you would never guess how easy it is, or that it has a sandwich condiment as a main ingredient. As I sampled one tiny taste after another, I found myself thinking, "What is mayonnaise, after all, but eggs and oil? Essential ingredients in any good cake!" With each passing bite, the idea of mayo in a cake became a little less outrageous. And with a quick dusting of powdered sugar, you've got a gorgeous, festive party offering that can be whipped up in a pinch.
You may still be skeptical, which I completely understand. Try it out at home first, or make one to bring into the office. I guarantee you it will not last long!
Emergency Chocolate Cake, from America's Test Kitchen Family Cookbook
2 c all-purpose flour
1 1/4 c sugar
3/4 t baking soda
3/4 c cocoa powder
1 1/4 c water
1 c mayonnaise
1 T vanilla extract (I used 1.5 T)
Confectioners' sugar for serving
Preheat oven to 350. Lightly coat an 8-inch square pan with butter. (I used an 8 inch round pan, the smaller area of which resulted in a cake that puffed up and got crusty like a brownie on the top--I highly recommend it.)
Whisk the flour, sugar, and baking soda together in a large bowl. In a separate bowl, whisk the cocoa and water together until smooth. Whisk in the mayonnaise and vanilla. Stir the mayonnaise mixture into the flour mixture until combined.
Pour batter into the pan and smooth the top. Bake until a skewer inserted into the center of the cake comes out with a few crumbs attached, 35-40 minutes. (It took closer to an hour for me, probably because of the different pan.)
Let cool, turn out onto a serving plate, and dust with confectioners' sugar.
Unveil it to oohs and aahs at your next holiday party, and when they ask how you made it? Give a smile and a wink, and tell them that's your little secret.