Piloncillo Sweet Potato Cake
Today I bring you cake and not just any cake. A cake inspired by the Mexican dish calabaza en tacha, where pumpkin is cooked way down in a spiced piloncillo syrup until soft as can be and then eaten with crema. It’s a meal usually prepared around Día de los Muertos and for the holidays, and a recipe I’d been attempting to perfect since October when the idea first nudged me. I see an ingredient, any ingredient, and my brain makes a direct line to cake.
Instead of pumpkin, I wanted to use sweet potatoes which felt more managable and would lend itself to preparation outside of the holiday season, and I don’t know about you but I’ve been ready to be done with the holiday season since the day after Christmas. In 2022 I made these pumpkin brown butter conchas, where the pumpkin pureé replaced the eggs. It was the same eggless idea here. Once very fork tender, and the piloncillo syrup has thickened and reduced by about half, pureéing the mixture gives us the base for cake. Not just any cake.
My decision to make this a vegan cake came from the prior knowledge that the sweet potatoes would have enough binding properties to hold the cake together. From there it was about figuring out the ratios to get the hydration right. I riffed and adapted this recipe based on this ginger piloncillo cake that I devloped back in 2021. Where I would normally add butter, I swapped in grapeseed oil; sweet potato replaced the eggs; oat milk, for the buttermilk.
My first couple attempts were severely underhydrated. Not enough liquid to replace from the eggs; too much flour; not enough sweet potato, too much sweet potato. The roller coaster of recipe developing. One the third test I got it right and was reminded how GOOD it feels to give the time and energy to an idea and see it all the way through. An idea that is now cake.
A vegan bake is not something I thought I’d be spending that time and energy on. I didn’t grow up with or experience vegan culture until well into adulthood, and I can count the number of vegan cakes I’ve eaten on one solid hand. Not really being snobby about it I just didn’t feel the need to seek out vegan cakes, and I genuinely enjoy working with eggs (meringue!), butter (good in everything), buttermilk (do I everrrr love using buttermilk especially in a cake for its tenderizing qualities). My job as a baker is to make delicious food. My job as recipe developer is to use ingredients in smart, creative ways that really showcase those ingredients. Using eggs here for this cake would mute the sweet potato and piloncillo flavor more than I felt I could live with.
It was really through the work of people I feel so fortunate to call friends though that I felt confident enough to wander into vegan baking (albeit very briefly and it wasn’t much of a challenge or risk considering I already knew sweet potatoes would give me my desired result). Andrea Aliseda is a leading voice to me as a vegan recipe developer and writer. Her work has been like technicolor in my mind, illuminating the ways that Mexican food can be translated and reinvented as vegan and vegetarian, while reminding us that vegan and vegetarian Mexican food has always existed.
Then there is my dear, sweet friend Gan Chin Lin. Lin’s Instagram is a delightful gaze into the creative ingenuity that is the heartbeat of vegan baking. Her recipe Patreon is where she teaches others how to do it ourselves. Through breads, cakes, cookies and more, Lin has shown me so much of what is possible in baking without dairy and eggs.
The writer and Le Cordon Bleu-trained pastry cook Caroline Saunders is doing exceptional work in the sphere of “climate-friendly baking.” Her newsletter Pale Blue Tart is a favorite of mine and one that has been an inspiration. Additionally, I very much enjoyed this recent Eater piece on the “Wonkafied world of vegan pastry”, featuring the works of Jen Yee of Baker’s Bench of Los Angeles, writer Alicia Kennedy (whose vegan Coconut Chai cake recipe I’ve made and absolutely adored), Jen Evans of Little Loaf Bakeshop in Poughkeepsie, New York, and Dominique Ansel (!), among many others. I’m grateful for the knowledge that vegan bakers have worked so hard to possess, and grateful they are generous enough to share with us.
Frost the cake however you'd like; I went with non-vegan meringue because I am frankly not interested in working with aquafaba. Whipped chocolate ganache would be amazing on this cake, as would simply dusting it with confectioner's sugar.
Swaps & Tips
You will need a minimum of 14 ounces of sweet potato. 14 ounces is the weight of the sweet potato before it’s been processed at all, before skinning and dicing into chunks. I’ve tested up to a whole pound of sweet potato and prefer the smaller amount in the final result of the cake. One large sweet potato should be good, but please weigh it out to be sure.
An immersion blender is what I used, HOWEVER you don’t need it. You just need some tool that will blend the sweet potato mixture. An upright blender would work, just be mindful to not blend it so much that the mixture becomes gummy. If you cook down the sweet potatoes until very, very tender you could probably even get away with simply mashing the mixture with a fork or potato masher.
I tested this with both cane sugar and dark brown sugar and prefer the added moisture from the molasses in the dark brown sugar. Granulated is a fine swap.
I frosted the cake with meringue (not vegan — it was 270 grams of egg whites which is from about 6 eggs, then 550 grams of sugar (double the amount of egg whites, as is true for any non-vegan meringue). Cook the egg whites + sugar over a double boiler until it reaches 160 degrees on a thermometer before whipping in a stand mixer. Torch it if you got it!
This recipe uses one single piloncillo cone. A note that some brands of piloncillo are sold as 8 ounce cones. I have tested the cake with both 6 ounces and 8 ounces of piloncillo and those two ounces truly did not make a lick of difference in the final result. Be patient as the piloncillo cone melts down and don’t be tempted to raise the flame to make it melt faster. This will only cause the water in the pan to evaporate.
I used oat milk here where I would normally use buttermilk and did not test with any other nondairy milks.
Grapeseed oil is my preferred neutral oil for baking; any other neutral oil will do in its place.
This recipe makes enough for a single layer 9x13-inch sheet cake, or two 8 or 9-inch round cake pans. The 9-inch cake pan will simply yield a thinner cake, I would check for doneness around the 25-27 minute mark.
For all recipes going forward I’m providing a handy little PDF link, which should take you to a recipe that you can print out and bring with you into the kitchen. There are sometimes weird formatting issues on my Substack recipes and I haven’t figured out what the deal is. The PDF should be much easier to read! Please let me know if there are any issues with the download link.
Piloncillo Sweet Potato Cake
Yield: One 9x13-inch sheet cake, or two 8-inch round cakes
335 grams (about 2 ½ cups) all-purpose flour
210 grams (1 cup) dark brown sugar
2 teaspoons baking powder
½ teaspoon baking soda
1 teaspoon kosher salt
14 ounces - 1lb sweet potato, peeled and diced into ½-inch chunks
1 (6 ounce) piloncillo cone
2 cups water
1 teaspoon ground cinnamon
320 grams (1 ½ cups) oat milk, room temperature
170 grams (1 cup) grapeseed oil
13 grams (2 teaspoons) vanilla extract
Spray a 9x13-inch cake pan with baking spray and line with parchment.
Weigh out or measure the dry ingredients into a medium mixing bowl; set aside.
Add the piloncillo cone and water to a wide, shallow pan set over medium heat. After about 10 minutes, the piloncillo cone should have melted completely; you may have to help it along by gently and carefully (strong emphasis on carefully) carving at it with the back of a spoon. Once it has melted and the mixture is gently boiling, add the diced sweet potato and ground cinnamon.
Cook sweet potatoes, stirring occasionally, on medium heat until very fork tender, about 15 - 20 minutes. The syrup should have thickened and reduced by about half. Transfer sweet potatoes with the syrup mixture to a large mixing bowl. Let cool just slightly.
Heat oven to 350F. Using an immersion blender, pureé sweet potatoes with syrup; some lumps are fine.
Pour the oat milk, grapeseed oil and vanilla extract into the bowl with the sweet potato pureé; whisk to combine. Sift in the dry ingredients and stir using a rubber spatula. The batter will be thick but pourable.
Transfer batter to the prepared cake pan and bake until a toothpick inserted into the center comes out mostly free of crumbs, about 30-32 minutes.
Let cake cool completely on a cooling rack before frosting however you’d like. If a quarter sheet cake is too much cake for your household, consider giving some away to friends, neighbors, or your local community fridge.