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Crispy Protein Churro Donuts

One of my favorite recipes here on my site is my Protein Churro Bites.

Since posting that recipe, it has definitely become a fan favorite, too.

Those churro bites are absolutely delicious, but I knew I could elevate them.

First and foremost, and I wanted to improve the flavor a little bit. But secondly, I wanted to shape them a bit differently.

Rather than try to make full-sized churros (I’ve tried it in the past, and trying to pipe them is a nightmare) I thought, why not go for churro donuts instead?


My friends, we’ve got a winner here.

These Protein Churro Donuts are crispy on the outside and soft on the inside, just like a real-deal churro.

Fluffy, packed with cinnamon and vanilla flavor, and yet… healthy?!

That’s right, each Churro Donut has only 105 calories and contains 6g of protein to boot!


Ingredients for Crispy Protein Churro Donuts

These Protein Churro Donuts use my little diet soda baking hack that I’ve used numerous times throughout my recipes.

My Funfetti Cupcakes, 3-Ingredient Pancakes, and Cookie Dough Cupcakes all utilize this trick!

Diet soda + cake mix

All you need to do is combine boxed cake mix with some diet soda or seltzer!

No eggs, no oil, no butter… just diet soda!

The carbonation makes the magic happen, and it results in the same exact light & fluffy cake you’d expect.

You can use any cake mix and any kind of soda you’d like. Want to use a chocolate cake mix and diet coke? You can do that!

For these donuts, we’re also adding some protein powder to the mix to make these Protein Churro Donuts, but if you truly want to omit it, you can!

I’m using PEScience protein powder, which is a blend of whey & casein protein. It’s what I love and always recommend, but if you want to use a different type of protein, you may be able to. We’re not using a huge amount, so it should be okay.


How are these donuts different from churro bites?

If you’ve made my Protein Churro Bites before (or at least read the recipe) there are three differences here… well, outside of the obvious shape difference:

  1. I bumped the protein content up slightly for these churro donuts. We don’t want to overdo it because it will dry out the donuts, but I bumped the protein up from 1 single scoop to 1 1/3 scoops of protein powder to get a little bit more protein.
  2. More cinnamon. I wanted these donuts to be nice and cinnamony on their own even if you didn’t add the cinnamon-sugar coating.
  3. Using vanilla cake mix instead of yellow cake mix. For my Protein Churro Bites, I went with a yellow cake mix. It’s not a huge difference, but I think using a vanilla cake mix leads to a much more authentic churro flavor.


How to make Crispy Protein Churro Donuts

These donuts require a very simple 2-step process: First, we bake some delicious protein donuts. Second, we crisp them up with a cinnamon-sugar coating in the air fryer to turn them into churro donuts.

To get things started, we just need to combine cake mix, protein powder, and cinnamon in a bowl. Then we add in some diet soda or seltzer and give it a light mix until it becomes a thick batter.

Spray a donut pan with nonstick spray and add the batter. Since the batter is thick, use a spoon to add it to each donut cavity.

You should have enough batter to fill a 6-donut pan.

Bake the donuts at 350 degrees F for 12 minutes.

They’re going to poof up quite a bit, and to be honest, I may have filled mine a little too much.

But hey, who doesn’t want a nice fluffy donut?

Now, we make the crispy churro magic happen.

Combine cinnamon & sugar in a bowl for your coating. I used a butter spray to help the coating stick to the donuts, but you can also use cooking spray or even some melted butter, if your prefer.

Spray the donuts all around, then roll them in the cinnamon-sugar mixture until fully coated.

Add to your air fryer basket, leaving enough room between each churro donut for them to fully crisp up all around.

I could comfortably fit 4 churro donuts in my air fryer basket, but it may differ for you depending on the size of your air fryer.

Air fry at 350 degrees for 5 minutes. Carefully flip the donuts (using tongs) halfway through.

When they’re finished, they’re going to look very dark and almost burnt. That’s okay! Just like my Healthier Cinnamon Crunch Bagels, even though they may look burnt, it’s just the melted cinnamon & sugar together.

It won’t taste burnt at all, I promise.

Now, CAREFULLY remove the churro donuts from the air fryer with tongs. The sugar is completely melted, and it’ll burn your fingers if you try to pick up the donuts.

Roll the donuts around in the cinnamon-sugar coating while they’re still hot (so the coating sticks).

Let the donuts cool for about 5-10 minutes to allow them to fully crisp up.

Then it’s time to enjoy!

These Crispy Protein Churro Donuts are going to be very crispy on the outside, but the inside is going to stay fluffy & moist, the way a donut should be.

These churro donuts are best served fresh, but they will keep for a few days. Just keep ’em in an airtight container or bag and you can enjoy them throughout the week!

Fair warning: these won’t be quite as crispy in the following days, so I highly recommend eating them fresh!

High-Protein Churro Donuts


Crispy Churro Donuts

Crispy Protein Churro Donuts

Yield: 6 Churro Donuts
Prep Time: 10 minutes
Cook Time: 18 minutes
Additional Time: 15 minutes
Total Time: 43 minutes

You would never believe that these donuts were healthy! They're crispy on the outside, soft on the inside, and packed with cinnamon churro flavor. Each donut is only 105 calories and contains 6g of protein.


For Donuts

For Coating


  1. Preheat your oven to 350 degrees F.
  2. In a large bowl, mix together the vanilla cake mix, protein powder, and cinnamon.
  3. Add the 1/2 cup diet soda/seltzer and lightly mix everything together with a silicone spatula until you have a thick batter. You don't want to aggressively mix the batter because it would flatten the carbonation of the soda, and that's the part that makes the magic happen.
  4. Spray your donut pan with nonstick spray and add your batter. It's going to be thick, so use a spoon to add the batter to each cavity instead of trying to pour it directly in.
  5. Bake for 12 minutes.
  6. Remove the donuts from the oven and let cool for about 15 minutes. You can leave them in the donut pan as they sit.
  7. Plug in your air fryer and let it preheat for 3-5 minutes at 350 degrees F. It won't take long for the air fryer to heat up, but it will go a long way in crisping up these Churro Donuts.
  8. Remove your donuts from the pan and lightly spray them with butter spray. You can use cooking spray or brush them with melted butter, too. Roll them around in the cinnamon-sugar mixture, then add to your air fryer basket. Leave space in between each donut in the air fryer to ensure they cook evenly- mine fit 4 at one time.
  9. Air fry at 350 degrees for 5 minutes. Flip the donuts halfway through (using tongs) to help them crisp up on each side.
  10. At the end of the 5 minutes, they're going to look very dark and almost burnt. That's okay- I promise they won't taste burnt. CAREFULLY remove your donuts with tongs (the melted sugar will burn you if you're not careful) and add them back into the cinnamon-sugar mixture to fully coat them.
  11. Allow the Churro Donuts to cool on a cooling rack for about 5-10 minutes, then dig in!


    • The protein powder I use is a blend of whey & casein protein, and I highly recommend that you use the same. Another type of protein powder should work, but I did not test this. To see how different types of protein powder affect donut recipes, check out my Ultimate Protein Powder Substitution Guide.
    • The donut pan I use is actually a tiny bit smaller than a standard donut, but that just means they're going to be thicker. If you have a normal donut pan, this recipe will still yield 6 donuts.
    • These donuts are best served fresh, but they are still great as leftovers. Just keep them stored in an airtight container and they'll stay fresh for a few days, although they may lose their crisp.
    • - No air fryer? You can add the cinnamon sugar coating and then bake these in the oven, although you will not get the same amazing crisp. If you go with the regular oven, bump the temperature up to 400 degrees F, and the 6 minute bake time should still work.

    I do not count the sugar substitute coating as part of my carb count. If you're super strict about carbs, you'll want to calculate your own nutrition.

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Nutrition Information
Yield 6 Serving Size 1 Churro Donut
Amount Per Serving Calories 105Total Fat 1gCarbohydrates 18gProtein 6g

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Tuesday 25th of October 2022

May I ask how you calculate the protein and carb

These were delicious by the way

Tha k you for posting and sharing!!!


Friday 28th of October 2022

Thanks Vanessa! I just plug everything into a macro-tracking app (myfitnesspal). The exact protein will vary based on the cake mix and protein powder you choose to use, of course. For carbs, I do not include the sugar substitute. Since it had 0 calories, including the grams of carbs often leads to a lot of confusion, so I choose to leave it out of the final total!


Wednesday 23rd of February 2022

You say these are best eaten fresh. Is there any reason that I can't stop the process after the baking step, then do the air frying part one donut at a time as I eat them? The baked donuts should last in the fridge for 6 days I assume?


Monday 22nd of November 2021

Made these today and they were fantastic. They were easy to make and didn’t require a ton of ingredients. I’ll definitely be making them again.


Monday 22nd of November 2021

Very happy to hear that, Melani! Glad you enjoyed them :)


Tuesday 27th of July 2021

Any vanilla cake mix? Suggestions? Thanks

About Matt Rosenman

With over 15 years of experience in health and fitness, Matt Rosenman is the expert voice behind Matt’s philosophy is simple: no foods are off-limits, and a healthy lifestyle shouldn't be complicated or restrictive. As a former certified personal trainer with a bachelor’s degree in Health Behavioral Sciences, Matt brings well-rounded expertise to his blog. From revamping classic recipes with a nutritious twist to breaking down fast food menus, his goal is make healthy living less confusing for everyone. Featured in major publications and with a strong following on social media, Matt is committed to making “healthy” uncomplicated—no matter where you are in your health journey. Join Matt on his mission to simplify health without sacrificing flavor. Learn More

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