Whether you’re celebrating a special occasion or you just feel like eating some cake, this protein cake recipe is going to change dessert for you forever.
Each slice of this double-layer protein cake contains 210 calories with 18 grams of protein, which is as impressive as any protein bar out there.
If you’d rather have fewer calories, you can easily make this as a single-layer protein cake, too.
Opting for a single layer will bring each slice down to just 120 calories while still containing 12 grams of quality protein.
Whether you’re in the mood for chocolate cake, birthday cake, or another flavor entirely, this recipe is extremely customizable.
Ingredients Needed for Protein Cake
I love keeping things simple, and that is exactly what we are doing with this recipe.
While you can certainly make your own cake from scratch, I like to take a little shortcut and use boxed cake mix.
I don’t consider it cheating, I consider it smart. If you want to whip up your own healthier cake mix from scratch using almond flour, coconut flour, or oat flour, go for it. But we’re going to roll with a pre-made cake mix to keep things simple.
To transform the cake mix into a high-protein treat, we’re going to be combining it with protein powder and diet soda or seltzer.
Mixing cake mix with diet soda is my favorite baking hack of all time, and I use it for tons of recipes because it eliminates the need for eggs or oil. Check out my protein mug cake recipe, cookie dough cupcakes, or cake mix protein pancakes to see this hack in action.
As far as the protein is concerned, I am using PEScience protein powder, which is a blend of whey protein powder and casein protein powder. This is the protein powder I use in all of my recipes because I’ve found it works best for baking.
If you prefer vegan protein powder, you can definitely make it work, so I’ll add notes to the recipe card below.
Lastly, I just want to note that you can use any flavor of protein powder you’d like. If you’re making chocolate protein cake, opt for a chocolate protein powder. If you’re going with vanilla or classic birthday cake (like Funfetti), stick with a vanilla protein powder.
How to Make a Double-Layer Protein Cake
You’ll be shocked at just how quickly and easily this protein cake comes together.
Once you’ve mixed up all of the cake ingredients in a large bowl, you’ll pour the cake batter into two separate 8″ round cake pans.
If you’d prefer to make a single-layer cake, simply cut the ingredients in half and go with one pan instead.
The cake pans will seem like they are not very full, but trust the process: they’re going to rise a ton in the oven.
Bake your two cakes in the oven at 350 degrees F for 15 minutes.
While the cake is in the oven, you’ll prep your high protein frosting. For the frosting, we have two options: a more traditional cake frosting or a higher-protein Greek yogurt frosting.
I went with the Greek yogurt frosting to maximize the total protein, but if I’m being honest, you definitely taste the yogurt. It has a perfect frosting consistency, but it’s still a yogurt base.
If you don’t enjoy the taste of yogurt, you can swap it out for cream cheese, but that will alter the nutrition facts quite a bit.
Or, you can go with a traditional frosting method: take some cake frosting (any brand) and mix it together with some protein powder, powdered sugar, and a little bit of almond milk to bump up the protein.
Going this route will increase the calories and total sugar, but when I crunched the numbers, the traditional frosting still resulted in a slice of cake with 240 calories and 16g of protein. Not bad!
After 15 minutes, remove your cakes from the oven and allow them to fully cool for about 20-30 minutes. It’s very important to allow the cakes to cool before frosting them or else the frosting is going to melt.
After they’ve cooled, we’re ready for the fun part! First, spread a thin frosting layer on top of one of the cake layers.
Top with your second protein cake layer, then cover your cake with the rest of the frosting. I ended up having just enough frosting for a thin layer on top of the entire cake, but if you prefer to be heavy-handed with your frosting, you may want to make a bit more.
Then all that’s left to do is decorate your cake! You can keep things simple (like I did) and add some sprinkles or chocolate chips, or go outside of the box and drizzle with some melted dark chocolate, peanut butter, or any other topping of your choice.
Slice the cake into 8 slices, and enjoy (bonus points for serving with ice cream, because cake is always better with ice cream on top). These cake slices are pretty large when you go with 8, but that’s how I prefer ’em.
If you need to save leftover cake, I like to keep mine stored in an airtight container in the fridge. Since I use the Greek yogurt frosting, I want it to stay fresh in the fridge. If you go with traditional frosting, you can keep the cake stored at room temperature.
Time Hack: Microwave Protein Cake
Don’t feel like waiting for the oven to heat up to bake a cake? You’re in luck!
I decided to test if this cake would work in the microwave, and it actually worked pretty well.
Follow the recipe as-is, but add the cake mix to a microwave-safe bowl. You’ll want to make sure you have a wide bowl (since you’re making a cake) and you can go with one or two layers just like the original recipe.
Mix your cake ingredients together in a large bowl, then spray your microwave-safe bowl with cooking spray before adding the cake batter.
Microwave for 3 minutes, and your cake will be ready to go!
I topped mine with some simple birthday cake frosting, and it tasted great. It’s definitely a little bit spongey compared to a baked caked, but hey, to have a cake in about 10 minutes total? I’m in.
More Protein Cake Recipes To Enjoy
Is an entire protein cake not enough to satisfy your sweet tooth? Don’t worry, I’ve got lots of other options for ya:
- High-Protein Chocolate Pancakes from Pancake Mix
- Microwave Pancake in a Mug in One Minute
- Protein Powder Mug Cakes in Just 60 Seconds
- High-Protein Oreo Cupcakes
- Light & Moist Protein Banana Bread
- Mini Low-Calorie Cheesecakes (With 10g Protein Each)
Protein Cake Ingredients (enough for two round 8" pans)
- 240g Cake Mix of Your Choice
- 120g (4 Scoops) Whey/Casein Blend Protein Powder (Flavor depending on which type of cake you are making)
- 1 1/2 Cups Diet Soda or Seltzer (any flavor)
Greek Yogurt Frosting (More Protein)
- 30g (1 Scoop) Whey/Casein Blend Protein Powder
- 40g Powdered Sugar Substitute
- 170g Plain Nonfat Greek Yogurt
- 20g Cocoa Powder (if making chocolate frosting)
Traditional Cake Frosting (Less Protein)
- Preheat your oven to 350 degrees F.
- In a large mixing bowl, combine your cake mix and protein powder. Slowly add your diet soda or seltzer to the bowl and stir until you have a smooth cake batter.
- Spray two 8" round cake pans with cooking spray and pour half of the batter into each pan.
- Bake the protein cake at 350 degrees for 15 minutes.
- While the cake bakes, prep your frosting. If making the Greek yogurt frosting, combine all of your dry ingredients in a bowl, then add the Greek yogurt to your dry ingredients to ensure you get a smooth frosting. If using the traditional frosting method, combine the dry ingredients with milk until you have a thick paste, then combine that with the cake frosting (if you don't mix the milk first it may become too gritty).
- Add the frosting to the fridge while the cakes finish baking.
- After 15 minutes, remove the cakes from the oven and them to fully cool for about 20-30 minutes. It's important to let the cake cool before frosting so the frosting does not melt.
- Remove your frosting from the fridge. Spread the frosting on top of one of the cake layers, then add your other layer on top before covering with the rest of the frosting.
- Add any toppings or decorations you enjoy (like sprinkles), cut into 8 slices, and enjoy!
- Keep any leftover cake stored in an airtight container in the fridge to keep the frosting as fresh as possible.
This cake can be microwaved for instant protein cake:
Use a wide microwave-safe bowl and microwave your cake for about 3 minutes (make 2 batches for both layers). It won't be quite as good as an oven-baked cake, but if you want cake in less than 10 minutes, it works!
- If you go with the traditional frosting method, each slice will have 240 calories and 16 grams of protein- still not bad at all!
- Oven temperatures tend to vary, so you may need slightly less or more bake time, but 15 minutes worked well for my cake.
- Vegan protein powder should work as a 1:1 replacement. I tried it in smaller quantities with my protein mug cake and it worked great.
- The nutrition facts below reflect a chocolate cake with Greek yogurt chocolate frosting- adjust accordingly if you change the recipe.
As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.
Nutrition InformationYield 8 Serving Size 1 Slice
Amount Per Serving Calories 210Total Fat 3gCarbohydrates 29gProtein 18g