This vegan chocolate sheet cake is unbelievably moist and fluffy with a decadent, vegan buttercream frosting. It's sure to be a hit at any party!
So, what exactly is a sheet cake, and how is it different from a regular cake? The answer is that sheet cakes are baked in a rectangular pan. They come in full, half and quarter sizes.
A full size sheet cake is normally baked in an 18x26 inch pan (that's big!). A half sheet is baked in a 13x18 inch pan. And, a quarter sheet is baked in a 9x13 inch pan.
You can technically use whatever pan you have on hand with this recipe. I've made a quarter sheet cake in a 9x13 inch pan. It takes 40-45 minutes to bake, and will obviously come out thicker than a half sheet or a full sheet cake.
If you are making a half sheet or full sheet cake, then you'll need to adjust the time. Take off 5-10 minutes for a half sheet, and 10-15 minutes for a full sheet. Basically, a thinner cake will require a shorter cooking time.
- Flour: We're using all purpose flour here, but if you'd like to make a gluten free vegan chocolate sheet cake, just sub in your favorite gluten free flour.
- Sugar: Caster sugar is the sugar of choice for this cake. The difference between granulated sugar and the caster sugar is basically the texture. Caster sugar has a finer texture. If you live in an area where sugar is processed with bone char, then please be sure that you find a brand that's marked as vegan.
- Soy Milk: Soy milk is my favorite plant based milk for baking, as it has the highest protein content.
- Apple Cider Vinegar: Soy milk (or any plant based milk for that matter) plus apple cider vinegar equals vegan buttermilk! Vegan buttermilk makes a great egg replacer.
- Vegan Yogurt: You can use soy or coconut yogurt. It will add a nice dense moisture to your sheet cake.
- Baking Powder and Baking Soda: These are both necessary leavening agents. They'll help your case rise.
- Vegetable Oil: Vegetable oil slows down gluten formation in cake baking - basically, it keeps your vegan cake moist!
- Coffee: Use the strongest coffee you have. Espresso, Nespresso, instant coffee - they will all work. Just be sure to use the coffee hot and undiluted. You won't taste it in your cake. It simply enhances the chocolate flavor.
- Vanilla: Vanilla is used in so many baking recipes because without it baked goods taste flat. I'd recommend buying a high-quality vanilla extract. It really makes a difference.
- Salt: Salt brings together all the flavors and makes them pop.
How To Make a Vegan Chocolate Sheet Cake
- In a small bowl, whisk together your soy milk and apple cider vinegar. Set it aside for at least 5 minutes. The milk will split, which gives you vegan buttermilk!
- Preheat your oven to 350 F (175 C). Line your cake pan with parchment paper leaving enough overhang to use as "handles" to pull the cake out of the pan. I used a 9x13 inch cake pan, but if you use a larger cake pan you'll need to reduce the baking time.
- In a medium sized bowl sift together all the dry ingredients (flour, caster sugar, cocoa powder, baking powder, baking soda and salt.)
- In a large bowl mix together your vegetable oil, vegan buttermilk, hot coffee and vanilla.
- Pour the wet ingredients into the dry ingredients. Mix the batter in a stand mixer or with a handheld mixture until there are no lumps in the cake batter. This shouldn't take longer than 30 seconds to one minute. Be careful not to over mix.
- Pour the cake batter into the prepared pan and bake for 40-45 minutes. Your chocolate sheet cake is done when a toothpick inserted in the center comes out clean.
- While the cake is baking, prepare your frosting.
- Add the vegan butter, cocoa powder, salt, vanilla and one cup of the powdered sugar to the a large bowl. In a stand mixer (or with a handheld mixer) beat until the a thick frosting starts to form.
- Add the rest of the powdered sugar one cup at a time, beating between each addition until all the sugar is mixed in.
- Now add the soy milk one tablespoon at a time until your frosting is the consistency you prefer.
- Make sure your vegan chocolate sheet cake is totally cool before you frost it. If it's too warm the frosting will melt.
- If you're feeling colorful, top with cocoa nibs, chopped nuts or sprinkles!
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Frequently Asked Questions About Vegan Sheet Cakes
Vegan sheet cakes are stored just like normal cakes. Basically, try to avoid refrigerating them. Wrap the cake in cling film and store at room temperature before frosting it. If you've already frosted your cake, store it at room temperature in an airtight container. Your cake should stay fresh for five days.
Yes, but I would suggest freezing it before your frost it. If you're making this cake ahead for a party, you can even freeze it in the tin, as long as you wrap the top in cling film. Defrost in the tin and then apply the frosting.
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Vegan Chocolate Sheet Cake
- 1 cup soy milk
- 1½ tablespoons apple cider vinegar
- 3 cups all purpose flour
- 2½ cups caster sugar
- 1 cup cocoa powder
- 1½ teaspoons baking powder
- 1 tablespoon baking soda
- ½ teaspoon salt
- ½ cup vegan yogurt
- ½ cup vegetable oil
- 1 cup strong coffee or espresso
- 1 teaspoon vanilla extract
For The Vegan Chocolate Frosting
- 3 cups powdered sugar
- ½ cup cocoa powder
- ½ teaspoon salt
- 1 cup vegan butter
- 4 tablespoons soy milk
- 1 teaspoon vanilla
- In a small bowl mix together the soy milk and apple cider vinegar. Set aside for at least 5 minutes.
- Preheat the oven to 350°F (175°C). Line a 9x13 inch sheet pan with parchment paper. Leave enough overhang to form handles to pull the cake out.
- In a medium sized bowl, sift together the flour, sugar, cocoa powder, baking powder,baking soda and salt.
- In a large bowl mix together the vegan yogurt, vegetable oil, vegan buttermilk, hot coffee/espresso, and vanilla extract.
- Add the wet ingredients to the dry ingredients. Using a stand mixer or a hand mixer, mix until there are no lumps - about 30 seconds.
- Pour the batter into the sheet pan and bake for 40-45 minutes, or until a toothpick inserted in the center comes out clean.
- Transfer the cake to a cooling rack and allow it to cool before frosting.
To Make The Vegan Chocolate Frosting
- Add the vegan butter, cocoa powder, salt, vanilla and 1 cup of the powdered sugar to a large mixing bowl. Using a stand or hand mixer, mix until a thick frosting starts to form.
- Add the remaining powdered sugar one cup at a time and continue mixing until everything is well combined.
- Add the soy milk one tablespoon at a time until the frosting reaches your desired consistency.