This keto white cake is everything a celebration cake should be-fluffy, moist, and spongy with rich vanilla flavor and creamy vanilla buttercream. If you’ve been on the hunt for a keto birthday cake that actually tastes like cake-not cornbread, not a brick, not something you politely choke down in front of your low-carb friends-this is it. This keto white cake has the soft, fluffy crumb and sweet vanilla flavor you’d expect from a classic celebration cake, plus a dreamy vanilla buttercream frosting that you’ll want to eat with a spoon.
What Makes This Keto Cake Special?
What sets this cake apart from all the other almond flour-based keto cakes out there? The secret’s in the texture-and trust me, that matters more than anything when you’re trying to recreate a traditional cake experience. Most low carb cakes end up dense, dry, or worse… greasy. The goal was to create a cake with bounce. Soft, cloud-like bounce.
Key Ingredients for the Perfect Texture
Two MVP ingredients make this possible: oat fiber and whey protein isolate. After a few test rounds and a couple tragic cake fails, this final version is everything you could want in a vanilla keto cake.
- Actually fluffy, like boxed cake mix fluffy.
- No coconut flavor or gritty mouthfeel.
- Zero weird aftertaste.
- Perfect for non-keto eaters.
- Customizable, so go ahead, stick some candles in it.
Ingredients
- Almond flour
- Oat fiber
- Whey protein powder
- Baking powder
- Salt
- Butter, preferably unsalted
- Sugar substitute (Allulose is recommended for best results)
- Eggs & Egg Whites
- Milk (unsweetened, non-dairy recommended)
- Vanilla extract
- Heavy cream (or coconut milk for dairy-free)
- Apple Cider Vinegar Or White Vinegar - Adds tenderness and lightness.
Step-by-Step Instructions
Preparing the Cake
- Preheat and Prep: Preheat oven to 350°F (180°C). Line two 8-inch round cake pans with parchment paper and lightly grease the sides with butter.
- Mix Dry Ingredients: In a large bowl, whisk together almond flour, oat fiber, whey protein powder, baking powder, and salt.
- Make the Cake Batter: In a stand mixer or hand mixer, cream your butter and allulose until fluffy, around 8 minutes. Add the eggs in, one at a time, and beat well until fully incorporated. Add the milk and vanilla extract until combined. While mixing with an electric mixer, pour the ingredients into the dry ingredients and stir until just combined.
- Bake: Divide the batter evenly amongst the two cake pans, and smoothen out the tops. Pour the batter evenly into the two cake pans. Bake for 22-25 minutes or until a toothpick comes out clean. Bake at 350°F (180°C) for 20-25 minutes, or until tops are set and a toothpick comes out clean.
- Cool: Allow to cool slightly, then invert them to cool completely on a wire rack. Allow the cakes to cool completely before frosting.
Preparing the Frosting
- Cream the Butter: In a large, clean bowl, beat the softened butter with an electric mixer until pale and fluffy (about 4-5 minutes).
- Add Sweetener: Add sweetener and beat until combined.
- Mix in Flavors: Mix in vanilla, then gradually add heavy cream until desired consistency is reached.
Assembling the Cake
- Prep: Place a small amount of frosting on a cake stand or turntable to keep the cake from moving around. If decorating directly on a cake plate or stand, slide four pieces of parchment paper underneath the edges of the cake for easy cleanup.
- Frost: Pipe frosting around the edge of the cake layer (optional), then evenly spread frosting over the cake.
- Layer: Repeat with the remaining layers, adding the layers upside down for a more level cake.
- Final Frosting: Add frosting to the sides and top of the cake, then use a bench scraper to smooth out the edges and the top and decorate as desired.
Essential Tips for Keto Cake Success
Let’s be real, keto cakes have a bit of a reputation. If you’ve ever bitten into a low carb cake that tasted like eggs, collapsed into a pancake, or had the texture of a sponge that’s been left in the sink too long… you are not alone. But don’t worry. These mistakes can be avoided.
Common Mistakes and How to Avoid Them
- Too Much Moisture, Not Enough Structure: Traditional flour gives baked goods a built-in fluff factor that almond flour just doesn’t have.
- Fix: Don’t swap out the protein powder or oat fiber unless you really know what you’re doing.
- Eggy Taste: Keto recipes love to throw a dozen eggs into everything, and it shows.
- Fix: This recipe uses just the egg whites, which keeps the structure without adding yolk-heavy flavor.
- Incorrect Butter Measurement:
- Fix: Make sure you’re measuring your butter correctly-melted, but not hot-and don’t sub out the oat fiber.
- Patience with Baking:
- Fix: Make sure your oven is fully preheated and don’t open the oven door until at least 20 minutes in.
Keto baking isn’t hard. It just plays by different rules.
Read also: Easy Low-Carb Cheese Crackers
Customization Options
There are plenty of ways to customize your birthday cake with different frostings.
- Keto cream cheese frosting
- Cashew cream cheese frosting
- Whipped coconut cream
- Chocolate frosting
Flavor Variations
- Funfetti: Mix sugar-free sprinkles into the batter before baking and decorate the top with them.
- Berry: Add sliced berries to the top and between the layers.
- Layer Flavors: Add Strawberry Lemonade Frosting or Low-Carb Vanilla Pastry Cream between the layers.
- Strawberry: Add sliced strawberries to the top and between the layers. Then, frost with whipped cream or sugar-free chocolate buttercream for chocolate strawberry.
- Coconut: Add coconut extract and decorate with unsweetened shredded coconut.
- Lemon: Replace the apple cider vinegar with lemon juice and add two tablespoons of lemon zest before baking. Then, add lemon zest and juice to the buttercream frosting.
- Chocolate: Turn this cake into a keto chocolate cake when you replace 1 tablespoon of the coconut flour with 2 tablespoons of cocoa powder.
Storage Tips
Once your cake is fully frosted (or even unfrosted), you can store it in the fridge for up to 5 days. If you want to make it ahead or save leftovers for later, this cake also freezes beautifully.
- To Thaw: Just pop it in the fridge overnight or let it sit at room temperature for about 30-60 minutes.
- Freeze: Place cake slices in a freezer-safe container and freeze for up to six months. Let them thaw overnight in the fridge. To freeze, place the cake on a sheet pan, uncovered, and freeze until solid. Then, wrap it in several layers of plastic and foil and freeze for 2 to 3 months.
Keto Vanilla Birthday Cake: FAQs
Can I use whole eggs instead of egg whites?
Technically, yes, but using whole eggs will give the cake a yellow tint and may change the texture slightly. If you want that classic white cake color and a lighter crumb, stick with egg whites.
What kind of protein powder should I use?
I recommend unflavored whey protein isolate. It blends well and helps fluff up the cake. Avoid casein or plant-based protein powders they absorb liquid differently and can make the cake gummy or dense.
Can I use collagen powder in place of protein powder?
Unfortunately, no. Collagen powder doesn't substitute well with protein powder in keto baked goods and cakes.
Read also: Keto Calorie Counting: A Detailed Guide
Can I substitute something else for oat fiber?
Oat fiber is a bit of a unicorn in this recipe. It helps create that light, spongy texture. You could try using coconut flour in its place but the flavor and texture may be slightly different.
Can I make this into cupcakes?
Absolutely. Divide the batter evenly into cupcake liners and bake at 350°F (180°C) for about 18-20 minutes, or until the tops are set and a toothpick comes out clean. This recipe also makes 24 cupcakes. After they have cooled, I recommend refrigerating them for an hour before frosting for a perfect crumb.
Is this a diabetic cake?
Please understand that I am not a medical professional. While I am knowledgable about diabetes and the diabetic way of eating (my father is diabetic), every person’s carbohydrate and sugar needs are different. I recommend speaking with a medical professional and/or registered dietician to see if this cake is suitable for you.
Can I make this without eggs?
I tried this cake without eggs, using an egg substitute. The texture was not super moist or fluffy but quite dense. If you don’t mind that texture, use a pre-formulated egg substitute (like Ener-g egg replacer). ** I haven’t tried using flax eggs or chia eggs.
Can I double or triple the mix?
For layered cakes, like mine pictured, it is safe to double or triple the recipe in both a stand mixer and the Thermomix®.
Read also: Magnesium Supplements for Keto
Can I use extra virgin olive oil instead of butter?
Extra virgin olive oil (EVOO) has a very strong flavour that will overpower the delicate vanilla flavour. If you want to substitute with olive oil, choose a light tasting olive oil instead.
Can I vanilla cake with coconut flour?
No, you can’t. The recipe would have to be completely different because coconut flour is very thirsty.
Can I skip the protein powder?
Gluten is a protein and in its absence, another dry protein powder helps baked goods rise and hold their shape. I do not recommend skipping it, nor do I recommend collagen or bone broth protein.
I don’t have almond milk, can I do heavy cream?
Heavy cream will weigh down this cake so you’re better off doing half water and half cream.