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Soft, fluffy, bakery-style high protein Funfetti cake that comes together in one bowl and delivers real cake texture with a serious protein boost.

I know its hard to meet your macros whilst indulging in a little goodness.

If you’ve tried a lot of protein recipes you know they are usually hit or miss but trust me , this one is worth it.

It bakes up light, slices cleanly, and still feels indulgent enough that you forget you’re eating a protein-forward cake.

A soft, fluffy high protein Funfetti cake packed with 24 grams of protein per slice, easy to make in one bowl, and finished with a creamy protein icing that tastes just like classic birthday cake.

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Why You Will Love This Recipe

Each slice packs 24 grams of protein without tasting chalky
Soft, fluffy crumb that stays moist even after chilling
One-bowl batter with simple, repeatable steps
Uses everyday grocery store ingredients
Great make-ahead option for the week
Protein icing adds sweetness without heaviness
Perfect for birthdays, meal prep, or random Tuesday cravings

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Dietary Benefits

This high protein Funfetti cake is designed for balance. It is not keto, but it is higher protein and lower fat than traditional Funfetti cake.

Each slice contains 24g protein, moderate carbs, and controlled fat, making it suitable for those following a high-protein or lower-calorie lifestyle.

It stores well, can be made ahead, and the macros are consistent slice to slice.

Net carbs are moderate due to flour and applesauce, so this is not appropriate for strict low-carb or keto diets.

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Ingredients You Need

All-purpose flour (1½ cups / 180g)

Provides structure. Do not substitute almond or coconut flour here. Those will drastically change texture and moisture balance.

Vanilla whey protein powder (3 scoops / 90g)

Use a whey-based protein, not plant-based. Plant proteins will make the cake dense and dry.

Zero-calorie sweetener (¾ cup)

Granulated monk fruit or erythritol blends work best. Liquid sweeteners will not provide the same structure.

Baking powder (1 tsp) + baking soda (½ tsp)

This combination helps lift the batter and prevents a gummy center.

Salt (pinch)

Balances sweetness and enhances flavor.

Fat-free vanilla Greek yogurt (1 cup / 220g)

Adds moisture and protein. Full-fat yogurt will increase calories and change macros.

Eggs (3 large)

Provide structure and lift. Do not replace with egg whites only.

Unsweetened applesauce (⅓ cup / 80g)

Adds moisture without excess fat. Do not skip or the cake will bake up dry.

Melted coconut oil (2 tbsp / 30ml)

Adds tenderness. Measure carefully.

Melted butter (1 tbsp / 15ml)

Adds flavor and softness. This small amount matters.

Cake batter extract (1 tsp / 5ml)

This gives the classic Funfetti flavor. Vanilla alone will not taste the same.

Rainbow sprinkles (2 tbsp)

Use standard jimmies, not nonpareils, which bleed color into the batter.

Protein Icing Ingredients

Fat-free vanilla Greek yogurt (½ cup / 110g)

Creates a thick but spreadable base.

Vanilla whey protein powder (1 scoop / 30g)

Adds protein and structure. Again, whey only.

Zero-calorie confectioners sweetener (½ cup)

Powdered texture is essential for smooth icing.

Step-by-Step Directions

Preheat your oven to 350°F (175°C). Grease a standard loaf pan thoroughly and set aside.

In a large bowl, whisk together flour, vanilla whey protein, granulated sweetener, baking powder, baking soda, and salt until evenly combined.

Add Greek yogurt, eggs, applesauce, melted coconut oil, melted butter, and cake batter extract to the dry ingredients.

Mix until just combined. The batter should be thick but scoopable. Do not overmix or the cake will bake dense.

Gently fold in the rainbow sprinkles, stirring just enough to distribute them evenly.

Transfer the batter to the prepared loaf pan and smooth the top.

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Bake for 40–45 minutes, or until the center is just firm to the touch and a toothpick inserted comes out mostly clean.

Remove from the oven and allow the cake to cool completely in the pan, then transfer to a wire rack.

For the icing, mix Greek yogurt, protein powder, and powdered sweetener in a bowl until smooth and thick.

Spread the icing over the cooled cake and finish with additional sprinkles if desired. Slice and serve.

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Tips for Success

Do not substitute plant-based protein. I tested it once and the cake turned dry and spongy.
Measure protein powder carefully. Too much will make the crumb tight.
Let the cake cool completely before icing or the frosting will melt and slide off.
If your batter seems overly thick, stop mixing. Overworking the batter is the fastest way to ruin the texture.
Use a light hand when folding in sprinkles to avoid color bleeding.

Frequently Asked Questions

Can I make this high protein Funfetti cake gluten-free?

Not with a direct substitution. Gluten-free flour blends change moisture absorption and structure.

How many carbs are in each slice?

Each slice contains 26g total carbs. Net carbs will vary depending on your sweetener choice.

How should I store this cake?

Store covered in the refrigerator for up to 5 days. The texture actually improves after chilling.

Can I freeze it?

Yes. Freeze slices individually without icing for best results. Thaw overnight in the fridge.