As a parent, and an eater, I am not about hiding vegetables in brownies.
So when my son and I were looking through Genius Desserts, the wonderful new cookbook from Food52, for something to bake together, and I saw a recipe for two-ingredient frosting that combines canned sweet potato puree and dark chocolate into a vegan ganache, I lost my mind a little. “Sweet potato frosting?” I yelled. “Shut the front door!” The almost-four-year-old found this hilarious, and began not just to repeat it, but also to demand that we make it.
I’m inherently skeptical of recipes that seem to be making something delicious into something healthy—those three-ingredient waffles that have made the vegan, gluten-free, and paleo recipe rounds are a rubbery, appalling lie. I only agreed to try this recipe because everything else we’ve used from the book has been so spot-on, and because it was so easy.
Genevieve Ko’s Two-Ingredient Chocolate Frosting has joined whipped cream and traditional chocolate ganache as my go-to cake toppers. To make it, you heat a 15-ounce can of pureed sweet potatoes on the stove until it bubbles. Turn off the heat, add in 10 ounces of bittersweet chocolate, and stir until smooth. Let it cool before you frost your cake. That’s it. It’s rich and chocolatey and there’s a pleasant earthy depth that suggests that maybe some sour cream went into the recipe. Except it’s vegan so long as you use dairy-free chocolate, and so much better than I anticipated.
I have abused the hell out of this recipe, using canned pumpkin (puree—pie filling will fail), just dumping in a bag of chocolate chips instead of weighing out nice chocolate, and on one occasion using 10 ounces of Hershey’s Kisses that ended up in my cupboard. Every time it’s delicious.
I asked Kristen Miglore, the author of Genius Desserts, why it works. “Chocolate in itself is an emulsion, and it has a lot of the things you are looking for in chocolately, mousse-y, creamy things,” she told me over the phone, noting that it is possible to make chocolate mousse out of just chocolate and water. “Chocolate, if you treat it right, can do a lot of things.” The cocoa butter in the chocolate provides fat, and the sweet potato lends its smooth, creamy texture to combine into a delicious frosting.
She also pointed out that the recipe plays up the earthier, less sweet side of chocolate. “It brings out the fruity qualities of chocolate, and more of the flavors of chocolate that you wouldn’t really see if you were putting a ton of butter or cream or other high-fat dairy in with it,” she said. She’s right: While this frosting could fly under the radar as a normal cake topper, it packs a complexity that icings made from butter and powdered sugar lack.
So what kind of cake should you top with it? To me, the point of this frosting is not that it’s vegan, but if you want to go in that direction, this vegan chocolate cake (secret ingredient: avocado) is moist and rich. Again, it doesn’t read as either vegan or healthy. I also think it would be great on banana bread cupcakes. The best combination I’ve tested so far is this frosting and buttery yellow cake, which has become a bit of a habit at my house—we call it Shut the Front Door Cake.