Fluffy Vegan Vanilla Sheet Cake with whipped buttercream frosting may be simple, but it's also the definition of delicious! This moist, homemade vanilla cake is perfect for parties, an emergency/short-notice dessert, and more!
2cupssoy milkor other vegan milk (480mL), room temperature
2cupsbrown sugaror cane sugar (400g)
3cupsall-purpose flour (360g)
2teaspoonsbaking soda(10g)
1teaspoonsea salt(2.8g)
⅔cupvegan buttermelted and cooled (150g)
1tablespoonvanilla extract
For the Whipped Buttercream Frosting
3-3 ½cupspowdered sugar
1cupvegan butter, softened
1teaspoonvanilla extract
1tablespoonvegan milk, add more if needed
¼teaspoonsea salt, only if using unsalted butter
Instructions
For the Vanilla Cake
Preheat the oven to 350°F/180°C. Prepare a 9×13 sheet pan (with sides) by greasing & flouring or lining with parchment paper (I usually just grease and flour).
In a small bowl or jar, add the apple cider vinegar and the soy milk together and stir to combine. It will curdle. Set aside.
Whisk together sugar, flour, baking soda and salt in a large bowl until thoroughly combined. Add milk mixture, melted butter and vanilla. Beat with an electric whisk on medium speed for about 1 to 2 minutes until everything is just combined. Scrape down the sides of the bowl and stir one more time to ensure everything is incorporated. Do not overmix.
Pour the batter into the pan. Tap on the counter three times lightly to remove any air bubbles.
Place the pan in the middle rack of your oven and in the center of that rack. Bake for 33 to 35 minutes until fully baked. Remove from the oven and let it cool completely in the pan.
After cooled, frost with buttercream frosting and sprinkles (optional!) Enjoy! For an even more moist cake, brush with simple syrup before putting on the frosting!
For the Whipped Buttercream Frosting
Beat the butter and vanilla for about 2-3 minutes with a stand mixer or a handheld mixer, until fluffy.
Add 1 cup of powdered sugar. Fold it in with a spatula so it doesn’t fly everywhere, then beat for about 1 minute. Add the rest of the powdered sugar in small increments too, until fully incorporated.
Add in a 1/2 tablespoon of vegan milk at a time until it reaches your preferred volume and consistency. Add that last ½ cup if you desire.
Then beat for about 5 minutes, using the spatula to mix everything together every other minute, until the frosting is fluffy, white, smooth and creamy.
Putting It All Together
Frost cake and decorate. The frosting will set at room temperature. Enjoy!
Notes
Tips for Success
If you're looking to speed up the cake-making process, you can prepare the frosting while the cake is baking, and then let it sit on the counter until the cake is done. Here are a couple more tips for you, should you need them:
For a Super Moist Cake: To get the moistest results with your vanilla sheet cake, brush it with simple syrup before putting on the frosting! It's not necessary but it's great for helping the cake last several days too.
Don't Over-Mix the Batter: Just beat or whisk the batter until everything has been combined. Too much mixing can lead to a cake that comes out dense or tough once baked.
Weigh the Flour: I highly recommend weighing the flour because that's the best way to accurately measure it. If you don't have a scale, though, you can spoon your flour into a measuring cup to avoid packing too much of it into your batter.
Let the Cake Cool Before Frosting: If the cake is still warm it can melt the buttercream, which will make it runny. To avoid that, let the cake cool completely, or put it in the fridge to speed up the process.