Sweet Potato Cake with Toasted Walnut Frosting

I’m assuming you’ve about had it up to here with carrot cake and other carrot-themed recipes by now, but allow me to suggest a gentle twist on the classic. This vegan sweet potato cake is moist and cinnamon-spiced like carrot cake is, but just different enough to be new.

The backstory to this vegan sweet potato cake is about what you’d expect. A certain popular carrot cake recipe on the internet tends to get made once or twice a year in my house; it’s great but I’ve always felt like I could tweak it a little bit to suit my tastes better. Then last week, I was staring down a surplus of sweet potatoes in my pantry and I thought to myself, “huh.” And then I got out my grater. And then the rest is history! Interestingly, I researched other sweet potato cakes and it seems like many of them call for cooked, mashed sweet potato. In this cake, they just get peeled and grated raw and mixed into the rest of the batter, carrot cake style. So while mashed sweet potato tends to make baked goods dense, you’ll find that this sweet potato cake is actually rather light and fluffy. I added to that effect by using the magical aquafaba instead of the more “traditional” flaxseed gloop, and the cake is better for it.

The effect of switching from carrots to sweet potatoes is a bit subtle. Sweet potatoes just have slightly more natural sweetness and so I was able to reduce the added sugar; they also have a flavor that’s a little more delicate, which called for some adjustments to my usual cashew cream frosting. I slathered the whole thing with a tangy toasted walnut version that will make you forget cream cheese ever existed; it’s just lightly sweet and the nutty flavors play perfectly with the sweet potato.

This design brought to you by Cake Decorating 101.

However, if you are planning to make this toasted walnut frosting then please be warned. Unless you have access to blanched walnuts or the patience to rub the skins off of the walnuts yourself, you’ll notice that weird things happen once the walnut is added. Everything turns sorta… purple. It’s hard to tell in the pictures because of the bright lighting and because the frosting was freshly made when I took these, but it’s purple alright, and the color intensifies as time goes on. I brought my little vegan sweet potato cake to a friend’s place and everyone happily ate it up without so much as a comment about this matter, so perhaps we can consider it a spring appropriate lavender hue. But definitely, if you’re expecting pristine snow white frosting then choose a different frosting recipe, or substitute additional cashews for the walnuts and top the cake with crushed walnuts instead.

Pet peeve! I can’t stand when I read a delicious sounding cake recipe online and then the recipe doesn’t include any clear photographs of what the interior of the cake looks like. I’m sure that in my old days on this blog I committed said cake sin myself. But not anymore! Just like with my vegan flourless chocolate cake, I went through a long photo session being extremely picky with the lighting to make sure you could see what this cake is really like. And as a result, writing this post has made me seriously consider baking yet another one.

Feel free to tell people that this vegan sweet potato cake is carrot cake if it’s more socially convenient to do so. The differences aren’t drastic; but that being said, I think this sweet potato version is delicious and special! If you give it a try, let me know in the comments or tag your creations on Instagram with #yupitsvegan and @yupitsvegan. Cheers!

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5 from 1 vote

Sweet Potato Cake with Toasted Walnut Frosting

For a new twist on carrot cake, try this cinnamon-spiced vegan sweet potato cake, slathered with a to-die-for toasted walnut frosting.

Course Dessert

Cuisine vegan, vegetarian

Keyword vegan sweet potato cake

Prep Time 30 minutes

Cook Time 40 minutes

Total Time 1 hour 10 minutes

Servings 12 slices

Calories 485kcal

Author Yup, it's Vegan

Ingredients

Dry ingredients:

• 275 grams all-purpose flour (see notes)
• 3 tsp baking powder
• 1 tsp baking soda
• 3 tsp ground cinnamon
• 1/2 tsp ground nutmeg
• 2/3 tsp kosher salt

Wet ingredients:

• 3 tbsp aquafaba (see notes)
• 1/2 cup unsweetened applesauce
• 3/4 cup unsweetened soy milk
• 3 tbsp orange juice
• 2 tsp vanilla extract
• 75 g coconut sugar (1/2 cup)
• 90 g cane sugar (1/2 cup)
• 6 tbsp grapeseed oil (1/4 cup + 2 tbsp)
• 250 g grated peeled sweet potato (about 2 cups packed)

Frosting:

• 1 and 1/2 cups raw cashew pieces soaked in water overnight
• 1/2 cup toasted walnut pieces
• 6 tbsp plain non-dairy yogurt (1/4 cup + 2 tbsp) (see notes)
• 6 tbsp maple syrup (1/4 cup + 2 tbsp)
• 3 tbsp refined coconut oil (or virgin if you don't mind the coconut flavor)
• 1 tsp vanilla extract
• 2 tbsp fresh lemon juice
• 1/4 tsp salt

Other:

• chopped toasted walnuts for garnish (optional)

Instructions

For baking the cake:

• Preheat the oven to 350 degrees Fahrenheit. Lightly spray two cake pans with oil.
• In a mixing bowl, whisk together all of the dry ingredients until combined.
• In a separate bowl, whisk together the aquafaba, applesauce, and soy milk. Add the orange juice, vanilla, and sugar, and stir until well-combined. Add the oil and mix vigorously until the oil is fully incorporated.
• Using a spatula, add the dry ingredients to the wet ingredients in 3 batches, gently stirring the mixture together between each batch. Stir until no large pockets of dry ingredients remain; small lumps are okay.
• Gently fold in the grated sweet potato and stir just until incorporated. Divide the batter evenly into the two prepared cake pans and gently smooth out the top.
• Bake for about 25 to 35 minutes, or until a toothpick inserted into the center comes out clean. For best results (especially if your oven tends to heat unevenly), rotate the positioning of the two cake pans at about the 20 minute mark, but avoid opening the oven until then. I usually make the frosting while my cakes bake.
• Place the cake pans on a cooling rack and let cool for an hour or so. You can then gently go around the edges with a sharp knife and then, one by one, carefully invert the pan, tapping on the bottom to release the cooked cake. Let cool completely before frosting.

For the toasted walnut frosting:

• Drain the cashew pieces and add them to a blender along with the walnuts. As best you can, blend the nuts into crumbs. Add the yogurt, maple syrup, coconut oil, vanilla, lemon juice, and salt, and blend the mixture until completely smooth. Depending on your type of blender, this may take several minutes, and stopping to scrape down the sides.
• Adjust lemon, salt, and maple syrup to taste if needed. Refrigerate the frosting in an airtight container to cool it until ready to frost the cake.

Vegan sweet potato cake assembly:

• Once the cake and frosting are cooled, place one of the cake layers upside down on your cake stand (or whatever your serving vessel is), so that the side that was the bottom during baking is facing up (this is the easiest way to get a flat surface for frosting).
• Take about half of the frosting and spread it out evenly over the top of the cake. If desired, sprinkle with toasted walnuts.
• Take the second cake layer, and place it on top of the frosted bottom layer. Spread the remaining frosting on top, and garnish with toasted walnuts to taste.
• Serve cold. Leftover cake will keep in the refrigerator for a couple of days.

Notes

FLOUR MEASUREMENT: If measured by scooping, the flour is approximately 2 cups. If you measure by spoon-and-level method, the flour is approximately 2 and 1/2 cups. For best results, measure by weight.

AQUAFABA: Aquafaba is bean cooking liquid. For this recipe, use the liquid from a (preferably BPA-free) can of chickpeas or white beans. If using homemade cooked beans, be sure to use the cooking liquid, NOT the soaking liquid, and if needed, reduce it on the stove until the consistency is slightly viscous.

NON-DAIRY YOGURT: Some people have trouble finding good non-dairy yogurt in their area. If this applies to you, just omit it and add another 2 teaspoons of lemon juice, plus a splash of non-dairy milk as needed to blend.

FLAT CAKE LAYERS: This cake doesn't tend to puff up a lot, so the layers should be even enough already to frost easily. If for some reason this isn't the case, use a very sharp knife to slice off and excess domed areas. You can then hide those extra cake pieces for yourself and snack on them later 🙂

NUTRITION: Nutrition facts include the frosting but not extra chopped walnuts for topping.

Nutrition

Serving: 1slice | Calories: 485kcal | Carbohydrates: 54g | Protein: 9g | Fat: 27g | Saturated Fat: 7g | Polyunsaturated Fat: 9g | Monounsaturated Fat: 10g | Sodium: 368mg | Potassium: 318mg | Fiber: 3g | Sugar: 24g | Vitamin A: 2950IU | Vitamin C: 5mg | Calcium: 60mg | Iron: 3.2mg

Adapted from Love and Lemons.