Vegan Oat Flour Cake
This post may contain affiliate links. As an Amazon Associate, I earn from qualifying purchases. Please read my disclosure.Soft, tender, and lightly sweet, this vegan oat flour cake is my gluten-free take on a classic vanilla dessert made with more wholesome ingredients. I use oat flour, vanilla extract, and plant-based milk to create a moist, spongy layer without needing any dairy or eggs! It takes just 1 hour to make and is ideal for birthdays, gatherings, or whenever you need a sweet treat.
Baking with oat flour has changed the way I approach gluten-free desserts, and this vegan oat flour cake is one of my favorite examples. Oat flour creates a delicate crumb while adding nutritional benefits, which makes it a great alternative to traditional cakes. I also love using it in my oat flour chocolate chip cookies, which I highly recommend if you enjoy baking.
I started testing this recipe when I wanted a cake that would please everyone in my family while also being vegan and gluten-free. It sounds like a tall order, but it was surprisingly easy to come up with. I leaned on 2 old faithful recipes which my family loves: gluten free brownies, and my healthy gluten free tres leches cake, for the flavor profile, and the rest is history. My kids almost always find something to be picky about, even when it comes to cake, but the first time I made this oat flour cake, they could not fault it.
👩🏽🍳 Why I Love This Recipe
When I want a cake that meets the approval of a nutritionist, I make this vegan oat flour cake. And yes, I am the approving nutritionist in question. Ha! I love this recipe because it is so delicious, but miles ahead in terms of nutrition when compared to standard cake recipes. The oat flour contains soluble fiber, which supports digestion and helps with steady energy while also providing high levels of phosphorus and manganese. I can also swap out the refined sugar for coconut sugar or maple syrup easily without affecting the flavor or texture.
The texture of this oat flour cake depends on how the batter is mixed and rested before baking, and I make sure to get it right each time for the softest crumb. I prepare a dairy-free buttermilk first and let it rest. Then I combine the wet and dry ingredients, and let the batter sit. Then I bake the cake until the center is just set and an inserted toothpick comes out clean, keeping the layers soft but structured.
My friend from the gym is on a strict gluten-free diet, and sometimes struggles to find vegan and gluten-free baked goods that have not been overloaded with sugar. I made this cake for her birthday 2 years ago, and she, in her words, fell in love. She did say it was a pity that I had made it for her party, as she would have preferred not to have shared it. Ha! No judgement.
This cake really is that good. Last year, I made the same cake for her birthday, which was shared among the guests. Before I left, I gave her a mini version with strict instructions not to share. If you follow a gluten-free or vegan lifestyle, be sure to give this cake a try. It has a quality that store-bought baked goods cannot compete with.
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🥘 Ingredients
For this vegan oat flour cake, I use a mix of flours and everyday plant-based baking staples. This is exactly what I use:
For the cake
Dry ingredients: I use gluten-free oat flour, arrowroot, baking powder, baking soda, salt, and coconut sugar to create a spongy base for my cake.
Unsweetened soy milk: I use soy milk to create a smooth batter, but any plant milk works in this recipe.
Apple cider vinegar: When combined with the milk, apple cider vinegar helps form a dairy-free buttermilk.
Olive or vegetable oil: This keeps the crumb soft and prevents the cake from drying out after baking.
Vanilla extract: I use this for that familiar cake flavor.
For the chocolate frosting
Powdered sugar: This creates a smooth texture, while also adding some shape to the frosting.
Unsweetened cocoa powder: I use this for a rich chocolate flavor that stands out against the mellow vanilla sponge.
Vegan butter: I whip this until light and fluffy to form the base of the frosting.
Vanilla extract: This adds a warm flavor to the mixture, which enhances the cocoa taste.
Unsweetened soy milk: I use this to adjust the consistency until it is spreadable.
🔪 How To Make
I make this vegan oat flour cake by building the batter in stages to control the texture. This is the process I follow:
Prep pan and oven: I start by preheating the oven to 350F and lining my cake pan.
Make buttermilk: In a small bowl, I whisk together the plant-based milk and vinegar and allow it to sit until thickened and slightly curdled.
Mix dry ingredients: Then, in a separate bowl, I combine the oat flour, gluten-free flour, arrowroot, sugar, baking powder, baking soda, and salt.
Combine batter: I pour the wet ingredients into the dry and stir gently until just combined.
Bake cake: I transfer the batter into the prepared pan and bake for 35-45 minutes or until a toothpick comes out clean.
Cool completely: Once it is done baking, I let the cake rest in the pan for 10 minutes before turning it out onto a wire rack to cool completely.
Whip butter: While the cake cools, I use an electric mixer to whip the vegan butter on high for a few minutes until fluffy.
Make frosting: Then I add the cocoa powder and powdered sugar in stages, before adjusting with milk and flavoring with vanilla.
Assemble cake: I slice the cake in half and spread an even layer of frosting over the bottom half of the cake before sandwiching it with the top layer. Then, I frost the top layer of the cake, and leave the sides “naked” so the layers are visible.
Decorate and serve: I finish by decorating with some fresh berries before slicing and serving.
💭 Expert Tips
My #1 Secret Tip for this vegan oat flour cake recipe is to let the batter rest for 5-10 minutes before baking. I keep repeating this because it is such an important step. Oat flour absorbs liquid more slowly than wheat flour, and skipping this part can lead to a dry and brittle texture. Giving the batter time to hydrate fully helps create a smoother, more consistent crumb.
Other Tips To Keep In Mind:
- Do not overmix the batter: I stop mixing as soon as the wet and dry ingredients come together. Oat flour does not contain gluten, but overmixing can still get rid of the air bubbles created by the leavening agents.
- Use room temperature butter: I take the vegan butter out of the fridge 30 minutes before making the frosting. Cold butter does not whip up light and airy, and the initial whipping stage is key to creating a creamy base.
- Always sift cocoa: I sift the cocoa and powdered sugar before adding them to the frosting, since cocoa powder has a tendency to clump easily. These clumps do not always break down during mixing, so sifting is the only way to get a silky finish on the frosting.
- Check early: Oat flour-based cakes can dry out a lot faster than wheat flour ones, so I always check for doneness at the 30-minute mark to avoid drying out the cake.
📖 Variations
I have tested a few variations of this cake depending on the occasion, and these are 3 I make most frequently:
Chocolate sponge: I replace 1/2 cup of oat flour with 1/3 cup sifted cocoa powder for a richer chocolate-based cake. I made this version for my eldest’s birthday because she said her favorite part of this cake was the chocolate frosting. Ha!
Citrus flavor: I add 2 tablespoons of fresh lemon juice and 1 tablespoon of lemon zest for a brighter flavor. I swap out the chocolate frosting for a vegan cream cheese frosting, which I have also flavored with zest. My husband likes this version when I use orange juice and zest, and keep the chocolate frosting.
Lower sugar: I reduce the sugar to 1/4 cup in the batter, and use half the frosting for a more health-conscious version. After eating this variation for a while, I was pleasantly surprised at how quickly my kids adapted to the lower sugar content. These days, I do not need to add too much for them to enjoy it.
🍽 Serving Suggestions
If you are planning on serving this cake for celebrations, I recommend keeping the presentation simple. I like garnishing the cake with a few fresh berries and some shards of my vegan peanut brittle. This cake also pairs extremely well with a warm cup of my creamy oat milk hot chocolate, especially on cold days.
The last time I made this cake was for a small family-only birthday gathering. Since it was my youngest’s birthday, I let him decide on the cake and the spread. The oat flour cake had to have extra frosting, with a side of vegan whipped cream, and a few frozen chocolate-covered bananas. I also added in some vegan Rice Krispie treats and earned myself some bonus mom points. Ha!
🧊 Storing And ♨️ Reheating
Refrigeration: I store frosted cake in an airtight container in the refrigerator for up to 4 days.
Freezing: I slice the cake and freeze individually wrapped portions, so I can thaw out only what I need. It keeps well for up to 2 months.
Reheating: If frozen, I let slices thaw in the refrigerator for a few hours, then bring them to room temperature before serving.
❓ Recipe FAQs
Can I adjust this recipe for cupcakes?
Yes! This recipe makes delicious cupcakes, and actually bakes up a lot faster. I divide the batter into lined cupcake tins, filling each one until it is 3/4 full. Then I bake for 18-20 minutes, but keep a close eye on them to prevent them from drying out. I let the cupcakes cool completely on a wire rack before adding my frosting to the top.
Why is my frosting grainy?
I have struggled with this before, and it is usually because vegan butter behaves a little differently than dairy butter. The most common reason for a grainy frosting is that the butter was not whipped long enough before the sugar and cocoa were added. I like giving my butter a full 2 minutes of whipping on its own. To fix a grainy frosting, I add 1 tablespoon of warm soy milk as the mixer is running to help smooth it out.
What can I use instead of arrowroot powder?
If I do not have arrowroot powder, I use tapioca starch or cornstarch in the same measurements as mentioned in the recipe. Both of these powders help bind the cake and improve the texture. This ingredient plays a key role in this recipe, especially since it does not contain egg.
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🎥 Watch How to Make It
Vegan Oat Flour Cake
Soft, tender, and lightly sweet, this vegan oat flour cake is my gluten-free take on a classic vanilla dessert made with more wholesome ingredients. I use oat flour, vanilla extract, and plant-based milk to create a moist, spongy layer without needing any dairy or eggs! It takes just 1 hour to make and is ideal for birthdays, gatherings, or whenever you need a sweet treat.
Servings: 18 slices
Calories: 326kcal
Ingredients
For The Cake
- 1¾ cups unsweetened soy milk
- 1½ tbsp apple cider vinegar
- 3 cups oat flour
- 1 cup gluten-free flour
- 1 tbsp arrowroot
- ¾ cup coconut sugar
- 3 teaspoon baking powder
- ¾ teaspoon baking soda
- pinch salt
- ½ cup olive or vegetable oil
- 1½ tbsp vanilla extract
For The Chocolate Frosting
- 1½ cup powdered sugar, sifted
- 1 cup unsweetened cocoa powder, sifted
- 1 cup vegan butter
- t teaspoon vanilla extract
- 4-5 tablespoons unsweetened soy milk
Equipment
- 8×8 Inch Cake Pan
- Electric Hand Mixer
Instructions
For The Cake
- Preheat the oven to 350 degrees F / 180 C. Line 8 inch round cake tin with parchment paper.
- Whisk together the soy milk and apple cider vinegar, set aside for 5 minutes.
- In a separate bowl mix together the oat and gluten free flours, arrowroot, sugar, baking powder, baking soda and salt.
- Pour the soy milk mixture, oil and vanilla extract into the flour mixture and stir until combined.
- Pour the cake batter into the prepared cake tin.
- Bake for 35-45 minutes or until an inserted skewer comes out clean.
- Remove and allow to cool for 10 minutes in the tin before turning out to cool completely on a cooling rack.
- When the cake has chilled completely, slice in half and set aside.
For The Frosting
- Add the vegan butter to a stand mixer or mixing bowl and use an electric hand mixer to whip the butter until light and fluffy.
- Add half of the cocoa powder and powdered sugar to the whipped butter and continue to mix until combined. Add in remaining cocoa powder, powdered sugar, vanilla extract and soy milk. Whip until fluffy and smooth. You may need to add a little more soy milk as you go, adjust the amount as needed.
- To decorate the cake – add an even layer of frosting to the bottom layer of the cake, top with the second layer of cake.
- Evenly distribute the remaining frosting over the entire cake and top with your favorite berries.
Notes
- My #1 Secret Tip for this vegan oat flour cake recipe is to let the batter rest for 5-10 minutes before baking. I keep repeating this because it is such an important step. Oat flour absorbs liquid more slowly than wheat flour, and skipping this part can lead to a dry and brittle texture. Giving the batter time to hydrate fully helps create a smoother, more consistent crumb.
- Do not overmix the batter: I stop mixing as soon as the wet and dry ingredients come together. Oat flour does not contain gluten, but overmixing can still get rid of the air bubbles created by the leavening agents.
- Use room temperature butter: I take the vegan butter out of the fridge 30 minutes before making the frosting. Cold butter does not whip up light and airy, and the initial whipping stage is key to creating a creamy base.
- Always sift cocoa: I sift the cocoa and powdered sugar before adding them to the frosting, since cocoa powder has a tendency to clump easily. These clumps do not always break down during mixing, so sifting is the only way to get a silky finish on the frosting.
- Check early: Oat flour-based cakes can dry out a lot faster than wheat flour ones, so I always check for doneness at the 30-minute mark to avoid drying out the cake.
Nutrition
Serving: 1slice | Calories: 326kcal | Carbohydrates: 40g | Protein: 5g | Fat: 17g | Saturated Fat: 4g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 9g | Trans Fat: 1g | Sodium: 143mg | Potassium: 253mg | Fiber: 4g | Sugar: 19g
Hi!!!!
Can I substitute arrowroot powder with corn flour? If yes same quantity like arrowroot?
Hi Vaishnavi! I haven’t tried using corn flour in this recipe, but theoretically it should work as a 1:1 replacement for the arrowroot powder! If you do try it with corn flour let me know how it turns out!
This cake was so delicious! Really enjoyed that chocolate frosting. Definitely a vegan treat worth making time and time again!
Wooohoo! So happy to hear that Gina!
What a beautiful cake! I love that this is allergy friendly and so full of flavor!
Aw thank you so much Angela! Enjoy!
Beautiful cake, I love the texture of oat flour.
Thanks so much Sue! I know right? It gives it such a light but hearty texture!
This is such an easy, versatile recipe. I especially love the carrot cake variation!
Yay! Thanks Renee!
Great recipe for indulging without the guilt! I will surely be making it again!
Thanks Tavo! So glad you liked it!