This light and fluffy Vegan Lemon Poppyseed Cake is easy to make and full of fresh lemon flavors. Topped with homemade Whipped Lemon Buttercream, it’s the perfect dessert for spring and summer!
I can never get enough of vegan desserts, but when a lemon dessert is placed in front of me, all bets are off! I can’t resist the bright and vibrant flavors of a vegan lemon cake, lemon loaf, or lemon blueberry bread.
This Vegan Lemon Poppyseed Cake is no exception, either. It’s a fluffy and moist cake with plenty of bright, lemony flavor! Bejeweled with poppyseeds, this is a crowd-pleasing cake that’s perfect for welcoming the sunny, warm weather of spring and summer.
The only way to make this one-bowl cake even better is by topping it with whipped lemon buttercream. It’s creamy, bright, and the perfect finishing touch to each bite.
Ingredients needed (with substitutions)
- Soy milk – Soy milk works best when making vegan buttermilk because it’s rich and curdles well compared to thinner varieties, such as oat milk. If you don’t have soy milk, use almond milk instead. Coconut milk does not work.
- Apple cider vinegar – The cake begins with vegan buttermilk, made from soy milk and vinegar, to give it a moist crumb and a subtle tangy flavor. If you don’t have apple cider vinegar, use lemon juice or white vinegar instead.
- Vegan butter – You need vegan butter both for moisture in the cake and as the base for the lemon buttercream.
- Canola oil – Another neutral vegetable oil will work just as well.
- Sugar – Granulated sugar is best, but coconut sugar or cane sugar will also work well.
- Lemon zest – Freshly grated lemon zest brings a beautiful brightness and undeniable zesty flavors to the lemon cake and buttercream. Don’t skip it!
- Lemon extract – Just 1 teaspoon of lemon extract gives the cake and buttercream their signature lemon flavors. You can use 1 tablespoon of lemon juice instead but the cake won’t be as lemony.
- Vanilla extract
- Cake flour – This is the secret to an incredibly fluffy, soft, and moist lemon cake. You could use all purpose flour as an alternative, but the results won’t be as fluffy or light. No cake flour at home? Make it yourself by whisking 3 cups of all purpose flour with 6 tablespoons of cornstarch.
- Baking powder
- Poppyseeds – Some recipes will have you soak the poppyseeds in milk or water before baking, but it isn’t a necessary step here. You can also omit the poppyseeds to make a plain lemon cake.
- Powdered sugar – For the icing.
How to make vegan lemon poppyseed cake
Find the complete recipe with measurements below in the recipe card.
Start by making the vegan buttermilk by measuring the soy milk in a glass measuring cup. Pour in the apple cider vinegar, then set it aside to curdle.
Beat the softened vegan butter, oil, and sugar in a bowl with an electric mixer until light and fluffy. Add the lemon zest, lemon extract, and vanilla extract next.
Now add the flour, baking powder, salt, and poppy seeds. Gently mix before slowly adding the soy milk/vinegar mixture. Mix until everything is just combined.
Pour the cake batter into the pan and bake until a toothpick inserted in the middle comes out clean. Set it aside to cool completely while you make the frosting.
Beat the vegan butter with an electric mixer until creamy. Add the powdered sugar, lemon zest, lemon extract, vanilla extract, and soy milk, then beat again until the frosting is fluffy.
Spread the lemon buttercream in a thick, swirly layer on top of the cooled cake. Then slice, serve, and enjoy!
Tips and tricks
- Don’t overmix the batter! Only stir the dry ingredients into the wet ingredients until just combined and no dry flour streaks remain.
- If you don’t want to use the vegan lemon buttercream, top the cake with vanilla buttercream, vegan swiss meringue buttercream, or vegan whipped cream instead.
- Leave the cake as-is or decorate it with candied lemon slices, sliced almonds, or extra lemon zest on top.
Frequently asked questions
Sure! Pour the batter into a lined muffin tin and bake for 22 to 25 minutes. Let the cupcakes cool completely before piping the icing on top. Use the tips in my Vegan Buttercream recipe to learn how to pipe frosting onto cupcakes perfectly.
Want poppyseed muffins instead? Check out my Vegan Lemon Poppyseed Muffins.
Pour the cake batter into two round 8-inch cake pans instead and bake for about 30 to 35 minutes. Once the cake layers are completely cool, add some of the lemon buttercream on top of one layer, top it with the second cake layer, and cover the tops and sides with the rest of the icing.
The iced cake will stay fresh for 4 to 5 days in the fridge. You can store the whole cake in the covered cake pan or the individual slices in airtight containers.
Yes, the unfrosted lemon cake can be stored in the freezer for up to 3 months.
Want more vegan cake recipes?
Vegan Lemon Poppyseed Cake with Whipped Lemon Buttercream
- 1 1/2 cups unsweetened soy milk
- 1 tablespoon apple cider vinegar
- 1/2 cup vegan butter, softened
- 1/2 cup canola oil
- 1 1/2 cups granulated sugar
- 2 tablespoons fresh grated lemon zest
- 1 teaspoon lemon extract
- 1 teaspoon pure vanilla extract
- 2 3/4 cups cake flour*
- 1 tablespoon baking powder
- 1/2 teaspoon salt
- 2 tablespoons poppyseeds
Whipped Lemon Buttercream
- 1 cup vegan butter, softened
- 4 cups powdered sugar
- 1 tablespoon fresh grated lemon zest
- 1 teaspoon lemon extract
- 1 teaspoon pure vanilla extract
- 2-4 tablespoons unsweetened soy milk
Make the cake
- Preheat the oven to 350 degrees F and line a 9×13 inch cake pan with parchment paper or simply grease well.
- In a glass measuring cup, measure your soy milk then add the apple cider vinegar. Let it sit for a few minutes to curdle (this is your vegan buttermilk).
- In a large mixing bowl using a handheld mixer (or a stand mixer using the paddle attachment), beat the softened vegan butter, oil and sugar together until light and fluffy, 1-2 minutes. Now add the lemon zest, lemon extract and vanilla extract and beat until smooth.
- Now add the flour, then sprinkle the baking powder, salt and poppyseeds on top of the flour. Begin mixing on low speed, and slowly add the milk/vinegar mixture. Scrape the sides and bottom of the bowl as needed. Mix until well combined, but do not over mix.
- Pour the cake batter into the prepared pan and bake for 35-40 minutes, or until a toothpick inserted in the middle comes out clean. Let the cake cool completely in the pan on a wire rack before frosting.
Prepare the whipped buttercream, frost and serve
- With a handheld or stand mixer with the paddle attachment, beat the softened vegan butter on medium speed until creamy.
- Now add the powdered sugar, lemon zest, lemon extract, vanilla extract and 2 tablespoons of soy milk. Beat starting on low speed and increasing the medium-high. Beat for 3-4 minutes, until fluffy and soft. If the frosting seems too thick, add a few more tablespoons soy milk. If it's too thin, add a little powdered sugar. It should be fluffy!
- Spread the frosting in a thick, swirly layer on the cooled cake.
- Slice, serve and enjoy! Cover the cake and keep in the refrigerator for 4-5 days.
- You may use another plant milk in place of soy. I’d recommend almond, cashew or oat milk. Coconut milk doesn’t work very well.
- Use cake flour if possible for the lightest crumb. If needed, you can substitute all purpose flour but the cake won’t be as light and fluffy. Gluten free all flour may work, but I haven’t tested it.
Best vegan cake I have made – wonderful lemon flavor and very moist. I followed the recipe exactly except for the frosting which was a store bought whipped vanilla which I sprinkled with additional lemon zest. Received rave reviews from both vegans and non vegans – will be making this cake often!
How fantastic the cake was a hit! Thanks for your fabulous feedback and review! Happy baking!