Sweets, Vegan Food

Chocolate & Vanilla Birthday Layer Cake with Cookie Topping


Please read through this post as I used box mix and irregular size pans for this! I give you tips for success below, and try to explain exactly how I made this smaller size layer cake.

Happy birthday to Greg! My fiancé (we get married in less than a month ah!), the other half of itslivb.com, and the creator of the newly established @gregsvegangourmet instagram page! So, naturally, I had to make a cake for the occasion. And it wouldn’t be a Liv B recipe without my famous chocolate chip cookies! This is a mini chocolate and vanilla layer cake, topped with vanilla buttercream, cookie dough and chocolate chip cookies. The addition of both cooked and uncooked cookies is just so me, haha! Greg loves everything to do with cookies so I knew he would love this cake. We basically stood at the counter eating it right before dinner, not even caring that we might not be hungry for the noodles we had planned. It was just TOO yummy!

Box mix?!

So, the actual cake though. I cheated! I used box mix. Shhh don’t tell!! But honestly, box mix is my favourite vegan hack, because a lot of the mixes you find at any grocery store are accidentally vegan! Meaning they don’t contain dairy, eggs, butter, etc in the actual mix. They normally call for eggs, milk and butter to be added, but I have found it super easy to sub vegan ingredients! I use vegetable oil, nondairy milk (or water, if it calls for water) and a few tbsp of applesauce to replace the eggs (usually 1 tbsp per egg). You can’t taste the apples and it turns out perfect every time!

How I did it…

This is actually a mini cake. I decided I wanted to make a cake perfect for two people, since we have had tons of sweets and parties already. We didn’t need a whole cake for the two of us, and I had a mini cake stand I really wanted to use for photos. So here’s how I did it.

I made two box cake mixes. Then, I used a large sheet pan (13 inches by 18 inches) and added one flavour to each side. I baked it, and then used a bowl (6 inches in diameter) that fit my cake stand to cut out cake rounds. If you want to know what I did with the “scraps” of cake that were left over after cutting out the circles, keep an eye out for Thursday’s blog post!!!

Sadly, right before frosting the cake, I had a casualty. One of my vanilla cake layers fell apart and could not be salvaged. So I made a 3 layer cake, but it should have been 4 layers!

This sheet pan is 13 inches by 18 inches and the cake layers ended up being about 1 1/2 inches thick once baked.

Can I make this a full size cake?

Yes! A box of cake mix will make two 8-inch round cakes. Feel free to just make 4 normal size cakes and stack em high!

Box mixes usually have directions for baking round cakes, sheet cakes and cupcakes on the back of the box. It takes a different amount of time for all 3 of those options, so make sure to check the box!

The frosting…

The vanilla buttercream recipe comes from my first cookbook, Liv B’s Vegan on a Budget! I’m sharing it here and you should definitely bookmark it because this recipe is super easy and sooo versatile. You can use it as a base for other frostings as well, by adding different extracts. Almond, vanilla and hazelnut extracts are my favourite!

The recipe uses vegan butter, and my current favourite is the Becel plant-based sticks. They have a great creamy consistency and convincing buttery flavour!

Because I cut the cake out of a sheet pan, the edges were very crumby. I actually didn’t mind the look of crumbs in the frosting, but if you use regular cake pans this will not be an issue. Baking is fun for me and I just roll with it! But if you like a cleaner looking cake, use actual cake pans to avoid the crumbs. 

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Double Cookie Birthday Layer Cake

  • Author: Liv B
  • Total Time: 3 hours (including cooling time)
  • Yield: 1 cake


Chocolate and vanilla layer cake, topped with vegan vanilla butter cream, cookie dough and chocolate chip cookie chunks.



(read the box to see how much oil, water and applesauce you will need! Each brand is slightly different, but the below amounts are pretty typical!)

  • 1 vanilla cake box mix
  • 1 chocolate cake box mix
  • 2 1/2 cups water or plant based milk
  • 6 tbsp apple sauce
  • 1 cup vegetable oil

Vanilla Buttercream:

  • 3/4 cup vegan butter, softened
  • 1 tsp vanilla extract
  • 2 1/2 cups powdered sugar
  • 2 tbsp plant-based milk

Cookie dough and cookies:

  • I always have cookie dough in the freezer! So I baked a couple cookies, and then used some of the cookie dough on top as well. Feel free to use whatever toppings you like!



  1. Make the cake mix: In two separate mixing bowls, add one box of mix to each. Add the required amount of oil, water and apple sauce to each bowl and stir until combined. A few small lumps are okay.
  2. Pour cake mixes into your baking pans or sheet pan. Bake according to package directions (mine took about 30 minutes).
  3. While cakes are baking, make the buttercream: place the vegan butter and vanilla in a large mixing bowl. Using an electric mixer, beat until combined. Add the powdered sugar 1/2 cup at a time, beating until fully incorporated. Beat in the milk 1 tbsp at a time, as needed, to create a thick, smooth and spreadable consistency.
  4. Remove cake from the oven and let cool completely before transferring to a wire rack.
  5. Frost the cake by adding a layer of frosting in between each layer, then spread on top and sides. Because I cut the cake out of a sheet pan, the edges were very crumby. I actually didn’t mind the look of crumbs in the frosting, but if you use regular cake pans this will not be an issue. Baking is fun for me and I just roll with it! But if you like a cleaner looking cake, use actual cake pans to avoid the crumbs. 
  6. Add cookie dough and cookies, or whatever toppings you prefer! Serve and enjoy!
  • Prep Time: 10 minutes
  • Cook Time: 30 minutes

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