Sourdough Vanilla Half Sheet Cake
This sourdough vanilla half sheet cake is so versatile! You can use it during the holidays to make homemade Christmas tree cakes or trifle desserts during summer. It’s also a great snack cake for birthdays or when you get a cake craving!
My husband and I love this cake in many recipes. It’s not overly sweet and the batter can be fermented overnight. I hope this recipe replaces vanilla box cake mix for you just like is has for us!
This post may contain affiliate links of items I know and love. Read our disclosure policy for more information. I NEVER use AI (artificial intelligence) to create content for Plum Branch Home. Recipes, blog posts, photos, videos, podcasts, social media content: everything is made from scratch by me, Molly LaFontaine. After developing my recipes, they’re tested 2x by my husband, Tyler, and I before publishing. What you see from Plum Branch Home is real. It’s made for a reason, tested, and loved!
If you want to make this recipe but don’t have a sourdough starter, no worries! Grab my free guide so you can make your own starter at home.
If you’re new to sourdough baking and feel hesitant, or you have questions, I’ve got something for you! I broke down the basics of what you need to know about sourdough baking in my free sourdough baking guide for beginners. I highly recommend grabbing a copy!
Vanilla Half Sheet Cake Made with Sourdough
My husband and I both aren’t huge cake people unless you’re talking about homemade sourdough cakes like this one! There’s something about this cake that makes you come back for more. You’re going to love it!
I first developed this recipe to use for my sourdough Christmas tree cakes. It’s the perfect cake for cutting out shapes with cookie cutters.
How Big is this Half Sheet Cake?
I use a pan that’s 10″ by 15″ with a rimmed edge. This makes my half sheet cake dimensions the same size and about 1 inch tall.
How Many People Does this Half Sheet Cake Feed?
That depends on how much each person will eat since it’s a shorter cake. I would say it could feed about 6-8 people depending on the slice size.
Why You’ll Love This Sourdough Half Sheet Cake
- It’s simple to follow and easy to make!
- It’s made with wholesome ingredients.
- It’s versatile so you can use if for many different occasions or recipes.
- You can replace boxed cake mix with this recipe.
- This cake is so fluffy and moist!
Sourdough Vanilla Half Sheet Cake Ingredients
- butter: make sure it’s softened. I like to use salted butter.
- avocado oil: you could use coconut oil but I don’t recommend olive oil.
- cane sugar: I like to use pure granulated cane sugar for a more wholesome option.
- eggs: make sure your eggs are room temperature by letting them sit out for an hour before baking
- pure vanilla extract: adds so much flavor.
- sourdough discard: aka unfed starter
- milk: I like to use whole milk
- sour cream: this makes the cake super moist. You can substitute it with plain unsweetened yogurt
- salt: I like to use sea salt
- baking powder: I use an aluminum-free option
- all-purpose flour: I use unbleached organic but you can use any
Substitutions & Variations
- Sour Cream Substitute: Instead of using sour cream you can use an unsweetened, plain yogurt.
- Cupcakes: For cupcakes, use a cupcake pan and bake a few minutes less.
- No Eggs: You can use an egg replacer powder if allergic or sensitive to eggs.
- Different Milk: You can use any milk you choose. Just make sure it’s not flavored or sweetened.
Helpful Kitchen Tools for this Recipe
This section contains Amazon affiliate links to items I use and love for this recipe.
How to Make Sourdough Vanilla Half Sheet Cake
Preheat oven to 350 degrees Fahrenheit. Grease and flour a rimmed half sheet pan (about 10″x15″)
In a large mixing bowl add softened butter, avocado oil, and sugar. Mix with an electric mixer (with beater attachments) on low speed for 2 minutes. It should be creamy and well-combined.
Add eggs one at a time. Beat each into the mixture on low speed until completely combined both times.
Add in vanilla, sourdough discard, milk, sour cream, salt, and baking powder. Mix on low speed just until combined. Do not over mix.
Add in flour (a little at a time) and mix on low speed just until combined. Do not over mix.
Optional – At this point you can either continue the recipe or place the batter, covered, in the fridge for 12-24 hours to long ferment for fermentation benefits.
Pour cake batter onto the prepared baking pan. Spread evenly with a spatula to fill the entire pan.
Bake & Cool the Half Sheet Cake
Bake for 20-24 minutes or until a toothpick comes out clean. (If you pan is differently sized please adjust your bake time a few minutes.)
Take the cake out of the oven and let cool in the pan for 5 minutes.
Then use a spatula to loosen the edges of cake around the pan.
Place a piece of parchment paper on top of the cake as well as a wire cooling rack.
Flip the entire thing upside down so that the wire rack is standing on the counter like it should. Remove the pan and your cake should come right out. Let cool completely before frosting and enjoy!
How to Make Long Fermented Sourdough Cake
To long ferment the cake, cover the bowl of batter with a lid, beeswax wrap, or saran wrap and place it in the fridge overnight or up to 24 hours. Do this for a minimum of 12 hours.
Storing Half Sheet Cake
The longer a cake sits, the more it will dry out, so it’s best to eat it in 2 days, but it’ll be good for 3-4 days.
Unfrosted Cake: Store cake in an extra large air-tight container, preferably made of glass. It can be stored at room temperature for 2-3 days.
Frosted Cake: Store it the same way except if you would like you can place a beeswax wrap or saran wrap over the frosting to keep it from smudging everywhere in the container.
IMPORTANT: If the cake is frosted and you used a whipped cream frosting it will need to be stored in the fridge.
Freezing & Thawing Cake Instructions
Freezing: You can freeze this cake in slices, unfrosted, in a freezer-safe container for up to 3 months. I recommend using a glass container so no plastic taste goes into your cake.
Thawing: To thaw, place the cake in the fridge overnight or on the counter for a few hours.
Molly’s Tips for Making Sourdough Half Sheet Cakes
- Do not overmix the batter! This is my best tip. For an airy cake, you’ll want to mix just until the ingredients are combined.
- Don’t over bake: Set the timer for the minimum time, test the cake with a toothpick for doneness, and adjust the bake time accordingly. It’s best to underbake and test then over bake and dry out your cake.
- Have fun! Baking cake is supposed to be fun, don’t let the process overwhelm you.
- Read the recipe first: It’s always important, no matter what recipe you use, to read the entire instructions before getting started.
Best Frosting For This Cake
You can use any kind of frosting for this cake! My husband and I really like buttercream and whipped cream frosting. Both taste amazing but if we had to choose our favorite it would be my homemade stabilized whipped cream frosting. It’s just so good!
FAQs
Sourdough adds helpful cultures to your cake giving it fermentation benefits!
Not at all! It’s the same steps as regular cake unless you want to long ferment the dough. And even that’s easy.
Discard works just fine for this recipe since we aren’t looking for a rise like bread.
Yes you can if you’d like. Just pour the batter into a cupcake pan and bake for less time.
Since cake doesn’t need the same rise as a loaf of bread, you can use discard (aka unfed starter).
More Sourdough Cake Recipes to Try
- Sourdough Coffee Cake
- Sourdough Lemon Pound Cake (half pound)
- Sourdough Carrot Cake
- Sourdough Christmas Tree Cakes
If you made this recipe, give it a 5-star rating below and share a photo on your social media stories! Be sure to tag @plumbranchhome
Recipe
Sourdough Vanilla Half Sheet Cake
Ingredients
- 6 Tbsp softened butter (I like to use salted)
- 2 tsp avocado oil
- 3/4 cup pure cane sugar (granulated)
- 2 eggs (room temperature)
- 1 tsp pure vanilla extract
- 1/2 cup sourdough discard (aka unfed starter)
- 3/4 cup milk (slightly warmed, not hot)
- 1/4 cup sour cream
- 1/4 tsp salt
- 2 tsp baking powder
- 1 1/2 cup all-purpose flour
Instructions
- Preheat oven to 350 degrees Fahrenheit. Grease and flour a rimmed half sheet pan (about 10"x15")
Make the Batter
- In a large mixing bowl add softened butter, avocado oil, and sugar. Mix with an electric mixer (with beater attachments) on low speed for 2 minutes. It should be creamy and well-combined.
- Add eggs one at a time. Beat each into the mixture on low speed until completely combined both times.
- Add in vanilla, sourdough discard, milk, sour cream, salt, and baking powder (wait to add baking powder if you’re doing the optional cold ferment step below). Mix on low speed just until combined. Do not over mix.
- Add in flour (a little at a time) and mix on low speed just until combined. Do not over mix.
- Optional – At this point you can either continue the recipe or place the batter covered in the fridge for 12-24 hours to long ferment for more sourdough fermentation benefits. When you’re ready to continue the recipe stir in the baking powder just before baking.
- Pour cake batter onto the prepared baking pan. Spread evenly with a spatula to fill the entire pan.
Bake & Cool
- Bake for 20-24 minutes or until a toothpick comes out clean. (If you pan is differently sized please adjust your bake time a few minutes.)
- Take the cake out of the oven and let cool in the pan for 5 minutes.
- Then use a spatula to loosen the edges of cake around the pan.
- Place a piece of parchment paper on top of the cake in the pan. Then place a cooling rack over the top of that so it’s laying right side up on the parchment paper.
- Flip the entire thing upside down so that the wire rack is standing on the counter like it should. Remove the pan and your cake should come right out. Let cool completely before frosting and enjoy!