Fruity Pebbles Protein Mug Cake

Mug cakes are all the rage, and this Fruity Pebbles Protein Mug Cake is low carb, high protein, and ready in minutes!  Can it get any better??

Fruity Pebbles cereal is the best out there. It’s my favorite childhood cereal, my favorite adult cereal, favorite cereal in general. That's why we had to make this fruity pebble mug cake, and of course, we packed it with protein. If you’ve been on our site, you’ve probably seen our fruity pebble protein bars that are all the rage, thanks to this classic cereal!

For this mug cake recipe, we use protein powder as a substitute for flour to keep it low in carbs and big in flavor. In a typical baked good, you need some flour to ensure the cake rises, but in mug cakes, we have a much higher percentage of leavening ingredients to protein so the protein powder works just fine. The best part is that this little cake has 8 grams of protein!

For the big flavor, we soak the fruity pebbles in the milk to really enhance that sweet cereal milk flavor! Wait, did you say you want more high-protein Fruity Pebble recipes? No worries, try some of our other fruity pebbles protein powder recipes: Fruity Pebble Protein Pancakes, Fruity Pebble Protein Cereal Bars, or Fruity Pebble Protein Ice Cream!

Jump to:

• Ingredients and Substitution Options
• How to Make a Mug Cake
• Watch How to Make This!
• Joy Tip!
• Quick Facts and Common Questions
• Want to Save This For Later? Here’s How!
• Try these other delicious recipes!
• Recipe

Ingredients and Substitution Options

All substitution options are a 1:1 substitution unless noted otherwise.

Fruity Pebbles:  The star of the dish! Fruity pebbles are also great because they are pretty low in carbs and gluten-free by nature, however, they are processed in a gluten facility so they cannot be certified as gluten-free.

Substitutions: Cocoa Pebbles or Frosted Flakes are also great cereals! You can also use your favorite cereal and then strain out the milk to just use the cereal milk and leave out the whole cereal pieces in the recipe.

Milk: Milk is necessary for this protein cake because protein powder absorbs so much liquid. We use coconut milk for ours due to its lightness and mild coconut flavor.

Substitutions: Your favorite unsweetened plant milk (unsweetened almond milk, coconut milk, rice milk, etc.) or cow’s milk can be used. Check out our post on substituting oat milk here!

Coconut Oil:  This is the fat in the cake. Fat helps to blend flavors and enhance flavors, like Fruity Pebbles! We love coconut oil because it gives a mild coconut flavor and some good healthy fats.

Substitutions: Avocado oil, melted butter, or another mild vegetable oil can be used. You can try using Greek yogurt for more protein as a substitute too, since it is a fat, but it has not been tested.

Vanilla Whey Protein Powder: The key ingredient making this a protein mug cake! We chose vanilla protein powder because it mixes well and acts similarly to flour. There's even Fruity Pebbles Protein Powder!

Substitutions: Any of your favorite whey protein powders can be used. Using different flavors will result in a totally different recipe. For example, chocolate protein powder will get you a chocolate cake!

Baking Powder: Baking powder provides the rise. It is a combination of baking soda (a base) and cream of tartar (an acid) that is activated with liquid.

Substitutions: You can make your own baking powder by mixing one part baking soda with one part cornstarch and two parts cream of tartar. You can also add an additional ¼ of a cup of yogurt and use ½ teaspoon of baking soda in place of the baking powder.

Pure Vanilla Extract: Vanilla is the essential baking ingredient. Like fat, it enhances other flavors and adds buttery notes without actually adding more butter.

Substitutions: You can use ¼ teaspoon of almond extract or butter extract or omit it altogether. Imitation vanilla can also be used.

Coconut Sugar: Just a smidge more sweetness! A spoonful of sugar, you can say. Coconut sugar helps to add some warm notes to an otherwise fruity dish, like adding brown sugar to grapefruit - yum!

Substitutions: Brown sugar, white sugar, agave, or maple syrup can be used.

Egg: Eggs are the binder or glue. When mixed in, eggs help keep all the ingredients together. Once cooked, they expand to create more air pockets for the baking powder reaction to occur.

Substitutions: Flax eggs or egg replacers, like this one from Bob’s Red Mill or one from Just Egg, can be used as an egg substitute. A banana, applesauce, and many other things can be used also. Check out our post on egg substitutes here!

How to Make a Mug Cake

Step one: Pour milk and half of the cereal into a LARGE mug and let sit for 5 minutes.

Step two: After 5 minutes, add the remaining ingredients to the mug and mix well. No need to mix dry ingredients and wet ingredients separately!

Step three: Microwave for 70-90 seconds, keeping an eye on it so it does not overflow. Let sit for 1 minute in the microwave before enjoying. The mug will be SUPER hot!!

Watch How to Make This!

Joy Tip!

Use a tall mug! Using a large mug is critical for mug cakes because they have so much leavener. Try to use one that is double the height as it is wide and at least three inches in diameter. Using a large mug is an easy way to make sure your cake doesn't overflow.

Quick Facts and Common Questions

How do you make a mug cake not rubbery?

Mug cakes are notorious for being rubbery because all of the ingredients are mixed at once and typically over-mixed. This means the gluten is developed and then cooked quickly, resulting in a rubbery cake. Because we are using protein powder, which does not develop gluten when over-mixed, the risk of a rubbery cake is much lower.

Why are mug cakes spongy?

A microwave mug cake usually has more leaveners than a typical cake to help it rise quickly. This is why a mug cake can be spongy in texture.

How does protein powder affect baking?

Whey protein powder typically does well in baking. Because it absorbs liquid and expands like flour, you can typically use ⅓ of a cup of whey protein to replace up to a cup of flour in more forgiving baked goods. Other protein powders, or too much powder can result in a dry, chalky texture.

Which is better - plant protein or whey protein?

For baking - it depends. Whet protein has less fiber than plant protein, and thus absorbs less water. Either is fine for baking, but if using plant protein when a recipe calls for whey, add 25% more liquid than the recipe calls for. If using whey protein when a recipe calls for plant, reduce the liquid by 25%.

Can I use Fruity Pebbles Protein Powder?

Sure can! Fruity pebble protein powder is supposed to have the exact taste of fruity pebbles so we think this would be a fabulous addition to the mug cake!

Want to Save This For Later? Here’s How!

To store your mug cake for later, simply cover it tightly in plastic wrap or an airtight container. Next time you are ready to reheat it, just microwave in 10-second intervals. Be careful to not overcook it to ensure you end up with a moist cake!

Try these other delicious recipes!

Lemon Meringue Pie With Biscuit Base

Cheesecake Without Cream Cheese

Nutella Tartlets With Graham Cracker Crust

3-Ingredient Chocolate Banana Mug Cake

Did you try this and love it? Leave us a review, we would love to hear from you!

Recipe