Growing up, I would only want one of two cakes for my birthday: an ice cream cake from Carvel (shoutout to my East Coasters), or a homemade funfetti cake.
There are few things better than funfetti. Frankly, I don’t think I’ve ever met anyone who didn’t love this flavor. Show me someone over the age of 25 that didn’t love Dunkaroos, and I’ll show you a liar. There’s just nothing not to love!
I bought myself some Pillsbury Funfetti Cake Mix for the nostalgia. I knew I wanted to try to make something with it, but I wasn’t quite sure what. After thinking about it for a while, I decided that it made the most sense to just use the cake mix the way it was intended, but give it a protein boost!
These cupcakes taste every bit like the funfetti cake you know and love, but with 10g protein per cupcake!
To healthify these, I did two things:
- Added protein powder (obviously)
- Used diet soda as my magical ingredient
Diet soda tends to be really polarizing due to the artificial sweeteners. Personally, I don’t drink soda at all, but only because the carbonation hurts my face. Call it a sensitivity or just a strange overreaction on my part, but I don’t handle carbonation very well. Either way, I’m not opposed to the artificial sweeteners, ESPECIALLY in such small quantities like we’re using here. We only need 1/2 cup of diet soda here, so it’s not much at all.
What does the diet soda do?
Many years ago, I learned that you could combine cake mix with diet soda to create a cake. Needless to say, I was extremely skeptical, but I gave it a try and was amazed to find that the cake came out perfect. I put it to the test and made my friend a cake with this method for his birthday, and he never even questioned it (I did end up telling him because I don’t like secrets).
If you have a complete cake mix that calls for some combination of eggs, water, and/or oil, you can replace them all with diet soda alone! It sounds crazy, I know, but it works perfectly. I used this strategy for my crumb coffee mug cake recipe, too.
The flavor of the soda doesn’t matter. I happened to choose this Mountain Dew, but you can even just use an unflavored seltzer. The key is to stick with a light colored soda, and not something like Pepsi or Coke. If you use this method to make a chocolate cake, then you should go for a darker soda, but for this, stick with something light. Seltzer, Mountain Dew, 7-Up, etc.
Can I swap the protein powder?
That’s a fun answer, huh? I know that many people use a whey protein powder, and that will PROBABLY work, but I didn’t test it. Let me rephrase- it will 100% work and your cupcakes will turn out, but I can’t promise they’ll taste as good. Baking with whey protein tends to lead to dry baked goods if some kind of fat source isn’t utilized, so you may end up with a dry cupcake. I used PEScience here because it’s a whey/casein blend, which tends to be the friendliest when it comes to baking. That, and I think it’s downright delicious- not overly sweet, and adds a great amount of vanilla.
If vegan protein powder is your style, you’re going to need to adjust the amount of liquid you use. Vegan protein, particularly pea protein, is super absorbant, so you’ll need extra diet soda. Similar to whey protein, I can’t guarantee the results will be quite the same, but it’s worth a shot if you can’t handle whey.
Making the frosting…
The frosting is where you have some room to experiment. Essentially it’s just a combination of cream cheese, vanilla protein, and powdered sugar. The beauty of this is that you can taste it and adjust based on your preferences. Some people have a huge sweet tooth, so you can easily add more powdered sugar.
I used the whey/casein blend in this frosting which makes a world of difference. The addition of the casein helps to create a much thicker frosting, where using whey protein alone will result in a much stickier frosting. Vegan protein would work great because it’s nice and thick.
If you do only have whey protein powder, add it last when making your frosting. By mixing everything else first, it will help to not create a suuuuper sticky frosting. But if you want the most authentic result, PEScience is the way to go (Quest is also highly recommended by many).
I also used a fat free cream cheese in this frosting. Fat free cream cheese doesn’t even come close to its full-fat alternative in the taste department, but it works well for this. Since we don’t necessarily need the flavor and just the texture, we can get away with it. That being said, you can certainly go for reduced fat or regular cream cheese, it will just obviously alter the nutrition slightly.
- 130g (1 Cup) Funfetti Cake Mix
- 31g (1 Scoop) Vanilla Whey/Casein Protein (I used PEScience)
- 1/2 cup Plus 2 Tbsp Diet Soda of Choice
- 84g Fat Free or Reduced-Fat Cream Cheese
- 31g (1 Scoop) Vanilla Whey/Casein Protein (I used PEScience)
- 1 tsp Vanilla Extract
- 20g Powdered Sugar Substitute (I used Swerve)
- 2 tbsp Milk of Choice
- 4g Rainbow Sprinkles (Plus extra for topping)
- Preheat the oven to 350 degrees F.
- In a large bowl, mix together the Funfetti cake mix and protein powder until they are fully combined. Slowly pour your diet soda into the mixture while stirring until a batter forms. I started with 1/2 cup but it wasn't quite enough, and an extra 2 tbsp was the perfect amount. If you use a different protein powder you may need slightly more or less liquid, so start with 1/2 cup and adjust as needed.
- Spray your muffin tin (I use a silicone one I found on Amazon which makes it very easy) and fill with your batter, being careful not to fill completely to the top so they do not overflow. Add to oven and bake for 15 minutes.
- While your muffins bake, prep the frosting. Mix all of the frosting ingredients together minus the sprinkles until it's nice and smooth. Since the cream cheese might be hard, it may be easiest to use an electric hand mixer, but it's not necessary- a silicone spatula will work as well. Once smooth, fold in your sprinkles, then add the frosting to the fridge to firm up.
- After 15 minutes, remove your cupcakes from the oven and carefully transfer them to a cooling rack (if you keep them in the muffin tin, they'll continue to cook). Let cool for 15-20 minutes before adding your frosting.
- Remove the frosting from the fridge and put it in a sealable sandwich bag. Cut the tip of the bag to create a piping bag and squeeze the frosting over your 6 cupcakes. You can also spread the frosting with a knife to make it easier. Top with some additional sprinkles and dig in!
You can store these for a few days if you don't eat them immediately, but if stored in the fridge, the frosting will begin to harden. If you don't plan to eat immediately, it's best to keep them unfrosted and then only frost them once ready to eat.
The protein powder I use is a blend of whey & casein. To see how different types of protein powder affect cake recipes, check out my Ultimate Protein Powder Substitution Guide.
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Nutrition InformationYield 6 Serving Size 1 Cupcake
Amount Per Serving Calories 140Total Fat 2gCarbohydrates 21gFiber 0.5gSugar 10gProtein 10g