Rich, moist and decadent vegan chocolate sheet cake with a rich chocolate frosting. Perfect for special occasions or just to satisfy a chocolate craving.
This vegan chocolate sheet cake makes a perfect celebration cake. I love making it for our birthdays since Jaye and I have birthdays within 6 days of each other (I’m a year older), and this makes enough cake for birthday week!
It really doesn’t hurt that a sheet cake generally gets more slices than a layer cake, so it goes further. Perfect for parties, or just when you want to have more servings of cake for yourself.
This cake is a real treat. It’s super easy to make, extremely moist and decadent and loaded with chocolate flavor.
Of course if you DO want to make a layer cake, then check out our most amazing vegan chocolate cake recipe.
And for a vanilla version of this cake, check out our vegan vanilla sheet cake.
Ingredients You’ll Need For The Cake:
Ingredient Notes
- Flax egg – this recipe uses 1 flax egg, which is a mix of ground flaxseeds and hot water. If you need a substitute for this, then you can use 3 tablespoons of applesauce instead.
- Vegan buttermilk – our vegan buttermilk is made from a mix of lemon juice and soy milk or almond milk. I prefer soy milk as it creates a thicker/richer buttermilk but almond milk does work if you prefer to use that.
- White vinegar – distilled white vinegar can be switched for apple cider vinegar if that’s what you have on hand.
- Canola oil – can be replaced with vegetable oil.
Ingredients You’ll Need For The Frosting:
Frosting Ingredient Notes
- Vegan butter – we used salted vegan butter. If you’re using an unsalted vegan butter then you can add a pinch of sea salt if you like.
- Soy milk – can be replaced with any non-dairy milk.
How To Make Vegan Chocolate Sheet Cake
You will find full instructions and measurements in the recipe card at the bottom of the post. This is a summary of the process to go along with the process photos.
- Sift all purpose flour and cocoa powder into a mixing bowl. Add white granulated sugar, light brown sugar, baking soda and salt and mix together.
- Prepare your vegan buttermilk by adding 1 and ½ tablespoons of lemon juice to a measuring jug and adding soy milk (or almond milk) up to the 1 and ½ cup line (360ml). Leave it for a minute to curdle.
- Prepare your flax egg by mixing 1 tablespoon of ground flaxseeds with 3 tablespoons of hot water from the kettle. Leave it for a minute to become gloopy.
- Add the vegan buttermilk, flax egg, canola oil, vinegar and vanilla extract to the mixing bowl and mix into a batter. Don’t over-mix.
- Transfer the batter to a 9×13 baking pan (sprayed with non-stick spray).
- Bake at 350°F for 30 minutes or until a toothpick inserted into the center of the cake comes out clean.
- Let the cake cool completely before frosting.
- Prepare your frosting by adding vegan butter, powdered sugar, cocoa powder, vanilla extract and soy milk to the bowl of your stand mixer. Starting at slow speed, gradually increase the speed until the frosting is thick and smooth.
- If your frosting is too thick, add a little more soy milk to reach the right consistency.
- When the cake is completely cooled, frost it with the chocolate frosting and decorate with chocolate shavings.
- Cut it into squares and serve.
Baker’s Tips
Measure the flour correctly. To get the perfect moist and fluffy cake, it’s crucial that you don’t accidentally over-measure your flour. So the best way to measure it is to weigh it out on a food scale. If you don’t have a food scale though, then the next best method for measuring flour is the ‘spoon and level‘ method. Spoon the flour into your measuring cup and then level off the top with a knife.
Don’t over-mix the batter, and bake it right away. When you’re mixing the batter, make sure you mix it just enough to combine and then stop mixing. Over-mixing the batter can affect the texture of your cake and cause it to be dense. You also want to pour it out into your 9×13 baking pan (or 10×15 baking pan, see below) and bake it right away. If the batter sits too long that can impact the texture and rise of your cake.
Baking pan sizes. We baked this sheet cake in a 9×13 baking pan for 30 minutes and this is what you see in these photos. It also works GREAT in a 10×15 baking pan. You will just get a larger, thinner cake. Baking time for 10×15 is 20 minutes. For a more classic style vegan Texas sheet cake, go with the 10×15 baking pan.
Make It Gluten Free
For a gluten-free version switch the regular all purpose flour for a gluten free all purpose blend.
Storing and Freezing
Keep it stored in an airtight container at room temperature for 2-3 days or in the fridge for up to a week. If you’re storing it in the fridge, then let it come to room temperature before serving.
You can also freeze this cake for up to 3 months. If your 9×13 baking pan has a lid, then just put the lid on it and freeze! Otherwise wrap it before freezing. Thaw it overnight in the fridge and bring to room temperature before serving.
More Delicious Vegan Cakes
Did you make this recipe? Be sure to leave a comment and rating below!
Vegan Chocolate Sheet Cake
Ingredients
For the Sheet Cake:
- 2 cups All Purpose Flour (250g)
- ¾ cup Cocoa Powder (65g) Unsweetened
- 1 cup White Granulated Sugar (200g)
- ½ cup Light Brown Sugar (100g)
- 1 teaspoon Baking Soda
- ½ teaspoon Salt
- 1 ½ cups Vegan Buttermilk (360ml) 1 ½ Tablespoons Lemon Juice + Soy Milk up to the 1 ½ cup line
- 1 Flax Egg 1 Tablespoon Ground Flaxseed + 3 Tablespoons Hot Water
- ½ cup Canola Oil (120ml) or Vegetable Oil
- 1 Tablespoon Distilled White Vinegar or Apple Cider Vinegar
- 2 teaspoons Vanilla Extract
For the Chocolate Fudge Frosting:
- ½ cup Vegan Butter (112g)
- 3 cups Powdered Sugar (360g)
- ¾ cup Cocoa Powder (65g)
- 1 teaspoon Vanilla Extract
- 4-5 Tablespoons Soy Milk or other non-dairy milk.
For Decoration (Optional):
- Vegan Chocolate Shavings
Instructions
- Preheat the oven to 350°F (180°C) and spray a 9×13 baking pan (*see notes for different sizes) with non-stick spray.
- Sift all purpose flour and cocoa powder into a mixing bowl. Add white granulated sugar, light brown sugar, baking soda and salt and mix together.
- Prepare your vegan buttermilk by adding 1 and ½ tablespoons of lemon juice to a measuring jug and adding soy milk (or almond milk) up to the 1 and ½ cup line (360ml). Leave it for a minute to curdle.
- Prepare your flax egg by mixing 1 tablespoon of ground flaxseeds with 3 tablespoons of hot water from the kettle. Leave it for a minute to become gloopy.
- Add the vegan buttermilk, flax egg, canola oil, vinegar and vanilla extract to the mixing bowl and mix into a batter. Don't over-mix.
- Transfer the batter to your prepared 9×13 baking pan.
- Bake for 25-30 minutes or until a toothpick inserted into the center of the cake comes out clean.
- Let the cake cool completely before frosting.
- Prepare your frosting by adding vegan butter, powdered sugar, cocoa powder, vanilla extract and 4 tablespoons of soy milk to the bowl of your stand mixer. Starting at slow speed, gradually increase the speed until the frosting is thick and smooth.
- If your frosting is too thick, add the remaining 1 tablespoon of soy milk.
- When the cake is completely cooled, frost it with the chocolate frosting and decorate with chocolate shavings.
Notes
- Measure the flour correctly. The best way to measure your flour is to weigh it out on a food scale. If you don’t have a food scale then the next best method is the ‘spoon and level‘ method. Spoon the flour into your measuring cup and then level off the top with a knife.
- Vegan buttermilk – I prefer soy milk for making vegan buttermilk as it creates a thicker/richer buttermilk but almond milk also works if you prefer to use that.
- Flax egg – if you need a substitute for the flax egg, then you can use 3 tablespoons of applesauce instead.
- Baking pan sizes. This recipe also works great in a 10×15 baking pan. You will just get a larger, thinner cake. Baking time will be 15-20 minutes (it’s usually ready right around 17 minutes).
- Make it gluten-free. For a gluten-free version switch the regular all purpose flour for a gluten free all purpose blend.
- Storing and freezing: Keep it stored in an airtight container at room temperature for 2-3 days or in the fridge for up to a week. If you’re storing it in the fridge, then let it come to room temperature before serving. You can freeze it for up to 3 months. Thaw it overnight in the fridge and bring to room temperature before serving.
Delicious, fluffy and perfect for parties!
Hi do you think you could reduce the sugar in this recipe? If so how much would you say to reduce it by?
Thank you 🙂
Hi Lea, we have not tried reducing the sugar, but you can certainly try it and see how you go.
Hi Alison, I’m a returning reader. I’ve been trying many of your vegan cakes and they have been surprisingly loved by my vegan in-laws! This time I’d love to make this cake. I am going to make some adjustments though: instead of cocoa powder, I’ll use carob powder since that’s all I can get now. I hope that wouldn’t be a problem? Also, would it be okay if I just omit the flax egg at all? Thank you very much for the recipes and I’m looking forward to making it next week!
Hi there! I think carob powder should be fine! For the flax egg you could replace it with 3 tablespoons of applesauce instead. I don’t recommend omitting it without replacing it as it will make the cake too dry. So happy you’ve been enjoying the recipes, hope this one works out great for you as well!
Hi Alison thank you so much for the recommendation! Unfortunately apple cannot be used due to an issue of someone. Last time you recommended me mashed pineapple instead of apple sauce, can I use that too as a replacement for the flax egg in this recipe? Thank you so much in advance! ::)
Yes sure that would also work!