Easy Gluten-Free Vegan Chocolate Cake with Healthier Sweet Potato Frosting
If you’re looking for a dessert that’s indulgent yet wholesome, this gluten-free vegan chocolate cake with sweet potato frosting is about to become your go-to recipe. Not only is this cake incredibly moist and chocolatey, but it’s also a fun nod to history.Â
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This “Crazy Cake,” also known as Wacky Cake, was born during the Great Depression when eggs, butter, and milk were hard to come by. But let me tell you, there’s nothing lacking in this cake—it’s got all the rich flavor you crave, plus a light, fluffy texture that makes it perfect for any occasion.
Why You'll Love This Recipe
This cake is a miracle on so many levels! It’s naturally free from gluten, dairy, and eggs, but you’d never know it. The cake is tender and moist, and the frosting is rich and creamy, all without any processed ingredients. Plus, the fact that you can make it without fancy tools or hard-to-find ingredients makes it a keeper in my book. Whether you’re celebrating a birthday, Halloween, or just the end of a long week, this cake has your back.
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And then there’s the frosting. Sweet potato frosting may sound unconventional, but trust me, it’s a game-changer. It’s velvety, chocolatey, and secretly packed with nutrients. Even my husband, who usually avoids sweet potatoes, loved it! So, whether you’re baking this cake for a Halloween treat or just need a special dessert to share with family and friends, this cake checks all the boxes: easy, budget-friendly, and 100% delicious.
What is Crazy Cake?
Crazy Cake (or Wacky Cake) was invented during the Great Depression when pantry staples like butter, eggs, and milk were scarce. Instead, it uses vinegar and baking soda for leavening, oil for moisture, and water or coffee to bring the batter together. The result is a light, fluffy cake that’s perfect for layering with frosting or enjoying all on its own.
Ingredient Notes
For the Cake:
- Gluten-free flour blend (or all-purpose flour): This is the foundation of the cake. A good gluten-free blend will give you that tender, light texture you want without needing wheat flour. It’s an easy swap, and honestly, no one will notice the difference.
- Granulated sugar (organic, unbleached): Sweetens the cake while also keeping it moist. I like to use organic, unbleached sugar because it’s a little less processed, but regular sugar works too.Â
- Unsweetened cocoa powder (Dutch-process or natural): The cocoa powder is what makes this cake deeply chocolatey. Dutch-process has a smoother taste, while natural cocoa is a bit more robust. Both work here, so use whatever you have on hand!
- Sea salt: A little pinch goes a long way in balancing the sweetness and enhancing the overall flavor. Salt and chocolate are a match made in heaven, trust me.
- Espresso powder (optional): This is totally optional but worth adding if you want to take that chocolate flavor up a notch. You won’t taste the coffee.
- Baking soda: This is what helps the cake rise and get that nice fluffy texture, especially since we’re not using eggs.
- Apple cider vinegar (or white vinegar): Paired with the baking soda, vinegar is the magic that makes this cake rise. It’s an old-school trick from the Crazy Cake days that really works!
- Unrefined cold-pressed extra-virgin olive oil: I love using olive oil in cakes for the moisture and richness it adds without making the cake heavy.
- Water (or cold brewed coffee): Both work to bring the batter together, but cold brewed coffee will give the chocolate a deeper, more intense flavor.
- Pure vanilla extract: Vanilla is key for adding warmth and rounding out all the flavors.
For the Sweet Potato Frosting:
- Sweet potatoes: Sweet potato puree is the base for this frosting, and it’s amazing how creamy and smooth it gets. It adds a natural sweetness and tons of nutrients.
- Semi-sweet chocolate chips: These melt right into the sweet potato and make the frosting rich and decadent. You can also use dark chocolate if desired.Â
- Unsweetened cocoa powder (or cacao powder): Cocoa powder gives the frosting its deep, chocolatey flavor.
- Unrefined virgin coconut oil: This gives the frosting its creamy texture and helps it set up nicely.Â
- Sea salt: A little pinch of salt is essential to balance the sweetness.
See the full recipe card below for exact ingredient amounts.
What Color Sweet Potato is Best?
You can use any color you want, however, the flavor profile varies. Here are some tips for each:
- Orange sweet potatoes: The sweetest variety. I recommend starting here first.
- White sweet potatoes: Less sweet, and more mild tasting.
- Purple sweet potatoes: Less sweet. You can add a little bit of pure maple syrup or sweetener of choice to sweet up the frosting.
Step-by-Step Instructions
This gluten-free vegan chocolate cake with sweet potato frosting is a total winner. The cake is moist, rich, and chocolatey, and the frosting is smooth, creamy, and surprisingly nutritious. Whether you’re making this for a special occasion or just because, it’s sure to be a hit with everyone—even those who think they don’t like sweet potatoes!
Preheat the oven to 350 F degrees. Lightly grease an 8 x 8-inch baking dish with olive oil and line with unbleached parchment paper.
In a medium bowl, whisk together the flour, sugar, cocoa powder, salt, espresso, if using, and baking soda.
In a large bowl, whisk together the vinegar, oil, water/coffee, and vanilla until emulsified.
Pour the dry ingredients into the wet and combine until no flour is visible.
Transfer the cake batter to the prepared baking dish and smooth the top with a spatula.Â
Bake for 25-35 minutes, until the center of the cake springs back. Let your cake cool on a wire rack.
Raise oven temperature to 425 F. Place the sweet potato on a parchment-lined baking sheet. Roast in the oven until very tender. The amount of time will depend on the size of your sweet potato. This could take 35 minutes or up to an hour. Let the sweet potato cool slightly. Peel and measure 3/4 cup of the sweet potato flesh. In a high-speed blender or food processor, puree the sweet potato, chocolate chips, cocoa powder, coconut oil, and salt until smooth like a frosting. If the sweet potato is still warm, the heat will help melt the chocolate. Otherwise, melt the chocolate in the microwave or over a pot of simmering water before adding to the blender. Frosting can be made up to 5 days in advance.
Spread frosting over the COOLED cake when ready to serve. The unfrosted cake can stay at room temperature for 2-3 days and then needs to be refrigerated.
Recipe Tips
- Don’t Overmix the Batter: Once you combine the wet and dry ingredients, stir until just combined. Overmixing can make your cake dense rather than light and fluffy, so stop as soon as you see no visible streaks of flour.
- Use Brewed Coffee: If you want to enhance the chocolate flavor, go for cold brewed coffee instead of water. It won’t make the cake taste like coffee but will deepen the chocolate flavor in the most delicious way!
- Frost When Cooled: I know it’s tempting, but don’t rush it! Make sure your cake has cooled entirely before frosting it. Otherwise, the sweet potato frosting could melt and slide off.
- Customize: This cake is perfect as-is, but it’s also a great canvas for adding your favorite touches. Sprinkle flaky sea salt on top for a sweet-salty contrast, add toasted coconut or chopped nuts, or even layer the cake for a more festive occasion.
- Extra Silky Frosting: If you want your sweet potato frosting to be extra smooth, let the sweet potato cool slightly before blending. Too hot, and you may end up with a runny consistency; too cool, and it can be stiff.
- Storage Tips: You can store this cake at room temperature for a couple of days, but if it’s frosted, I recommend popping it in the fridge after the first day. Just make sure to bring it back to room temp before serving to keep that perfect texture.
Why Sweet Potato Frosting is a Fantastic Alternative to Buttercream
Traditional buttercream, while undeniably delicious, is usually loaded with butter and powdered sugar, which can be a little heavy and overly sweet. This healthy frosting offers a lighter, more wholesome option without sacrificing flavor or texture.
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Here’s why it works so well:
- Naturally Sweet and Creamy: Sweet potatoes have a built-in sweetness, so you don’t need to rely on lots of sugar. Their creamy texture also blends beautifully into a smooth, luscious frosting that mimics the richness of buttercream (or cream cheese), but without all the butter or dairy.
- Nutrient-Dense: This frosting is packed with whole food ingredients, vitamins and nutrients. Sweet potatoes are high in vitamin A, fiber, and antioxidants. It’s a sneaky way to add a little extra nutrition to your dessert!
- No Powdered Sugar Needed: Sweet potato frosting doesn’t require any powdered sugar to thicken or sweeten, which makes it a great option if you’re looking to avoid refined sugars.
- Allergy-Friendly: This frosting is a great option for those with dairy allergies or sensitivities, since it’s naturally dairy-free and vegan.
Recipe FAQs
Can I make this cake ahead of time?
Absolutely! You can bake the cake a day or two in advance and store it at room temperature. The frosting can also be made up to 5 days ahead and stored in the fridge. Just give it a quick stir or let it come to room temperature before spreading it on the cake.
Can I use a different type of flour?
Yes! While I love using a gluten-free flour blend to keep this cake gluten-free, you can also use regular all-purpose flour if gluten isn’t an issue. The texture will be just as delicious.
How do I know when the sweet potato is done roasting?
Your sweet potato is done when it’s fork-tender. The skin should be slightly wrinkled and the flesh should be very soft. You want it to be soft enough to easily puree into a smooth frosting.
Can I freeze this cake?
Yes! This cake freezes well, both frosted and unfrosted. Just wrap it tightly in plastic wrap and store it in an airtight container in the freezer for up to 3 months. Thaw at room temperature before serving.
How else can I use sweet potato frosting?
You can put it in a piping bag and use it on top of cupcakes, for first birthday cakes (no added sugar!), in between the layers of your favorite cakes, on cookies, and more!Â
More Gluten-Free Desserts
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Easy Gluten-Free Vegan Chocolate Cake with Healthier Sweet Potato Frosting
Ingredients
Cake:
- 1 1/2 cups gluten-free flour blend like Bob’s or King Arthur or all-purpose flour
- 1 cup granulated sugar I use an organic unbleached sugar
- 1/4 cup unsweetened cocoa powder Dutch-process or natural
- 1/2 teaspoon sea salt
- 1/2 teaspoon espresso powder optional
- 1 teaspoon baking soda
- 1 Tablespoon apple cider vinegar or white vinegar
- 1/3 cup unrefined cold-pressed extra-virgin olive oil + more for greasing pan
- 1 cup water or cold brewed coffee
- 1 teaspoon pure vanilla extract
Sweet potato frosting:
- 1 medium sweet potato about 9 ounces, leave the skin on, scrubbed clean
- 1/4 cup plus 2 Tablespoons semisweet chocolate chips
- 2 Tablespoons unsweetened cocoa powder or cacao powder
- 1 Tablespoon unrefined virgin coconut oil, melted
- Pinch sea salt or to taste
Instructions
- Preheat the oven to 350 F degrees.
- Lightly grease an 8 x 8 -inch baking dish with olive oil and line with unbleached parchment paper.
- In a medium bowl, whisk together the flour, sugar, cocoa powder, salt, espresso, if using, and baking soda. In a large measuring cup or bowl, whisk together the vinegar, oil, water/coffee, and vanilla until emulsified. Pour the dry ingredients into the wet and combine until no flour is visible. Transfer batter to the prepared baking dish and smooth the top with a spatula.
- Bake for 25-35 minutes, until the center of the cake springs back.
- Raise oven temperature to 425 F. Place the sweet potato on a parchment-lined baking sheet. Roast in the oven until very tender. The amount of time will depend on the size of your sweet potato. This could take 35 minutes or up to an hour. Let the sweet potato cool slightly. Peel and measure 3/4 cups of the flesh. In a blender or food processor, puree the sweet potato, chocolate chips, cocoa powder, coconut oil, and salt until smooth like a frosting. If the sweet potato is still warm, the heat will help melt the chocolate. Otherwise, melt the chocolate in the microwave or over a pot of simmering water before adding to the blender. Frosting can be made up to 5 days in advance.
- Spread frosting over COOLED cake when ready to serve. Cake can stay at room temp for 2-3 days and then needs to be refrigerated.
Notes
- Don’t Overmix the Batter: Once you combine the wet and dry ingredients, stir until just combined. Overmixing can make your cake dense rather than light and fluffy, so stop as soon as you see no visible streaks of flour.
- Use Brewed Coffee: If you want to enhance the chocolate flavor, go for cold brewed coffee instead of water. It won’t make the cake taste like coffee but will deepen the chocolate flavor in the most delicious way!
- Frost When Cooled: I know it’s tempting, but don’t rush it! Make sure your cake has cooled entirely before frosting it. Otherwise, the sweet potato frosting could melt and slide off.
- Customize: This cake is perfect as-is, but it’s also a great canvas for adding your favorite touches. Sprinkle flaky sea salt on top for a sweet-salty contrast, add toasted coconut or chopped nuts, or even layer the cake for a more festive occasion.
- Extra Silky Frosting:Â If you want your sweet potato frosting to be extra smooth, let the sweet potato cool slightly before blending. Too hot, and you may end up with a runny consistency; too cool, and it can be stiff.
- Storage Tips: You can store this cake at room temperature for a couple of days, but if it’s frosted, I recommend popping it in the fridge after the first day. Just make sure to bring it back to room temp before serving to keep that perfect texture.
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