It doesn’t have to be your birthday to make birthday cake protein bars! You guys LOVE our peanut butter chocolate chip and pumpkin protein bars. I had some sprinkles on hand and hence this cake flavor was born!
We always have some protein snacks on hand during the week. I love adding protein powder to homemade bars, energy balls, muffins, and desserts. It’s such an easy way to boost the protein content and help make them more filling.
Each bar packs 15 grams of protein. They are sweetened with protein powder and a little bit of maple syrup. They make a great snack, pre or post-workout snack, or even a healthy dessert.
Plus making them at home is so much cheaper than buying store-bought ones, especially good-quality ones. And you know exactly what goes into them!

Why we love these homemade birthday cake protein bars
- they give you the birthday cake flavor but no baking is required!
- come together in about 20 minutes (10 minutes of that are them setting in the fridge) and are easy to make
- high protein with 15 grams of protein per bar
Ingredients
- creamy cashew butter – look for cashew butter with just cashews and salt. It needs to be creamy!
- almond milk
- maple syrup – for a little sweetness, but you can leave it out
- vanilla extract
- almond extract – this helps give it that cake batter flavor
- vanilla protein powder – this acts as the “flour” to the bars and helps the ingredients come together
- salt
- rainbow sprinkles – I love these all-natural ones (colored with natural ingredients)

How to make birthday cake protein bars
- Line a bread pan with parchment paper and set aside.
- Mix wet ingredients. To a medium mixing bowl, add cashew butter, milk, maple syrup, vanilla extract, and almond extract and mix to combine.
- Add dry ingredients. Add protein powder and salt and mix until a dough forms. If needed, add a little more milk. Add in sprinkles and carefully mix to combine.
- Form into bars. Press the mixture into the bottom of the pan. If desired, place in the fridge for 15 minutes to firm up some (I like doing this). Cut into 6 equal-sized bars and enjoy!


Can I use another protein powder?
I have just tested this recipe with plant-based protein. You can try a different protein powder, but you will need to adjust the recipe. Protein powders vary by consistency and how dense they are, so I would add a little less than the recipe calls for and add as you need for the best consistency. You can always add, but you can never take away!
- plant-based protein – follow the directions as written. I used this plant-based protein.
- whey protein – since whey protein is not as absorbent as plant-based, you might have to use a little more of it or cut back on the liquid (milk). I suggest leaving out the milk and mixing the batter. Then, add your liquid to help them come together, or add more protein if the texture is too wet. You could also add some flour if it is too sticky. Then stir in your sprinkles. I like this whey protein.
- collagen – I have not tried this recipe with collagen and I’m not sure it will work since collagen dissolves so easily. The protein powder helps the bars come together.


Can I add frosting to birthday cake protein bars?
What’s a cake without frosting? While I wanted to keep these super simple, you totally can. Here are a few suggestions:
- greek yogurt frosting – simply mix greek yogurt with a little maple syrup and vanilla extract and spread all over the bars.
- protein powder frosting – mix together a scoop of protein powder with a little milk until frosting-like consistency forms.
Add more sprinkles on top of your frosting if you like!
Tips for homemade protein bars
Here are a few tips to help ensure the best homemade protein bars:
- make sure to mix your cashew butter well – when using all-natural nut butter, the oil can separate and sit on the top. Make sure to mix well so it is thoroughly combined.
- use a thicker protein powder – the protein powder is what absorbs the liquid and is the flour of the recipe. You do not want one that dissolves easily in things (like collagen), or you will have to use a lot more. I used the brand Orgain and it works really well. See above for suggestions on using another kind.
- if your batter is too wet – if for some reason the batter is not coming together, you can either add more protein powder or flour. I would suggest absorbent flour like oat flour, almond flour, or coconut flour. Add little by little until desired consistency.
- use salt!! – it helps bring out the flavor. Don’t skip it!
Storage
- fridge – store in the fridge for up to a week in a tightly sealed container to keep the air out. If exposed to the air for too long, they will dry out some.
- freezer – freeze for up to 6 months. I suggest freezing individually and then defrosting the night before you want to eat.

Substitutions
- creamy cashew butter – any nut butter or seed butter will work, but it will change the flavor some. Cashew butter has a nice neutral flavor that works well.
- almond milk – any kind of milk will work. Water will also work.
- maple syrup – honey will work instead. Leave out if your protein powder is really sweet.
- almond extract – this is what gives it a cake-like flavor. There is no substitute.
- vanilla protein powder – I like vanilla plant-based protein because it adds some sweetness and the consistency works the best. You will want a thicker consistency to help absorb the liquid of the nut butter. I find plant-based protein usually has that. If you don’t have plant-based protein, you can substitute your favorite protein, but I would be careful of the ratios. See above for suggestions.
- rainbow sprinkles – any kind of sprinkles will work.
More homemade protein bar recipes
If you love quick and easy meals and want to learn how to build a balanced plate, check out our FREE How to Build a Balanced Plate Guide!


Birthday Cake Protein Bars
ingredients
- 3/4 cup creamy cashew butter (192 grams)
- 1/4 cup + 1 tablespoon almond milk (see notes)
- 1 tablespoon maple syrup
- 2 teaspoons vanilla extract
- 1/4 teaspoon almond extract
- 1 cup vanilla protein powder (100 grams – see notes)
- pinch of sea salt
- 2 tablespoons rainbow sprinkles (plus more for sprinkling on top)
instructions
- Line a bread pan with parchment paper and set aside.
- Mix wet ingredients. To a medium mixing bowl, add cashew butter, milk, maple syrup, vanilla extract, and almond extract and mix to combine.
- Add dry ingredients. Add protein powder and salt and mix until a dough forms. It will get crumbly at first but will come together (see notes if not). Use your hands if needed. If needed, add a little more milk. Add in sprinkles and carefully mix to combine.
- Form into bars. Press the mixture into the bottom of the pan. Place in the fridge for 10 minutes to firm up some (I like doing this). Cut into 6 equal-sized bars and enjoy!
Janet says
Another great protein bar recipe! Didn’t think I would love another one as much as your pumpkin protein bars, but this one is fantastic too!
Kelly says
Haha, I love to hear that! Thanks for trying them Janet and glad you enjoyed them!
Greg says
Quick and easy. taste delicious.
Kelly says
Thanks, Greg!!
Christine C says
Yum! Just made them. Wondering how long they would keep in the fridge. 4 days?
Christine says
fridge – store in the fridge for up to a week in a tightly sealed container to keep the air out. If exposed to the air for too long, they will dry out some.
Feeling dumb now
Kelly says
Haha, no worries! So glad you enjoyed them!
Dad says
Love them
Kelly says
Glad you enjoyed them!