Flourless High-Protein Custard Cake with Fruit (230 Calories)

Published on May 04, 2026

  by   Kristina Stosek

2 reviews

Prep Time: 10 minutes Cook Time: 50 minutes Serves: 6
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This Flourless High-Protein Custard Cake with Fruit is one of the easiest desserts I’ve made in a while. It’s naturally gluten-free, made with just 8 ingredients, and has only about 230 calories per slice. If you love simple desserts like this, you might also like my Flourless Chocolate Ganache Mini Cake.

Flourless high-protein custard cake slice on a glass plate with fresh flowers, gluten-free dessert

The texture is what makes this grain-free dessert stand out. It bakes up golden and puffed, then settles into a smooth, light custard with a cheesecake-like feel, without using cream cheese. I used mandarin oranges here since they’re in season, but you can easily swap in whatever fruit you have.

It’s simple, reliable, and one of those recipes that works the first time.

Why This Grain-Free High-Protein Custard Cake Is Worth Making

  • High-protein dessert made with everyday ingredients
  • Only about 230 calories per slice (depending on fruit)
  • No flour, no cream cheese
  • Just 8 ingredients
  • Works with fresh or frozen fruit
  • Light, creamy texture that slices clean once chilled

Similar to my Keto Mini Blueberry Cheesecakes (Low-Carb, Gluten-Free Dessert), this recipe relies on simple ingredients to create a rich texture without flour.

Ingredients for This High-Protein Custard Cake

Flourless custard cake ingredients with mandarin oranges, eggs, sour cream, and tapioca starch

(Measurements are in the recipe card below)

  • Fruit (I used mandarin oranges) you can use berries, or sliced bananas, pears or apples. If you use bananas toss them in pure cocoa powder instead of cinnamon…omg delicious!
  • Gluten-Free ground cinnamon. Not all spices are gluten-free because of cross-contamination.
  • Tapioca starch. You can use cornstarch but then it is no longer grain-free and is GMO
  • Sugar (I used fine coconut sugar) you can use white granulated sugar or monk sugar for low carb version.
  • Sea salt
  • Sour cream, or use full fat plain Greek yogurt. The cake will not taste as creamy.
  • Eggs
  • Vanilla extract. I have also tried it with 1 teaspoon of maple extract, also tasty flavor

How to Make This Flourless High-Protein Custard Cake (Step-by-Step Overview)

Step 1: Prepare the fruit
Toss fruit with 1 tablespoon of sugar and cinnamon. This adds flavor and helps it settle nicely into the batter.

Step 2: Mix the custard batter
Whisk together the dry ingredients, then add eggs, sour cream, and vanilla. Whisk well until smooth, this batter needs a good mix, just not whipped.

Eggs, sour cream, and vanilla in bowl for high-protein custard cake batter

Step 3: Assemble the cake
Pour the batter into a lined springform pan and scatter the fruit evenly over the top.

Custard cake batter in lined springform pan before baking, gluten-free dessert

Step 4: Bake
Bake until lightly golden. The cake will rise noticeably in the oven.

Flourless custard cake fully baked and risen in springform pan

Step 5: Cool and chill
As it cools, it will deflate, this is expected. Refrigerate until fully set before removing from the pan.

Flourless custard cake settled after cooling, showing custard texture

Tips for the Best Flourless Custard Cake Texture

  • Whisk thoroughly so the batter is smooth, but don’t whip air into it
  • Do not open the oven for the first 30 minutes
  • Bake until lightly golden on top
  • Let it cool completely, then chill before slicing
  • Remove from the pan only after chilling so the parchment releases cleanly

Why This High-Protein Dessert Works

The structure comes from the eggs and sour cream, but the real key is the tapioca starch. It gives the cake just enough stability while keeping it soft, creating that light cheesecake-like texture, without adding cream cheese or flour.

What to Expect After Baking

This cake will rise as it bakes, then settle as it cools. That’s what creates the custard texture.

The center should feel set, not loose. If you gently press the top, it should hold and not collapse.

Make-Ahead Option (Highly Recommended)

This cake is best made ahead. After chilling overnight, it slices cleanly and the texture fully develops, perfect when you want dessert ready to go.

Serving Ideas for This Flourless Custard Cake

  • Drizzle with maple syrup or honey
  • Top with extra fresh fruit, similar to my No-Bake Chocolate Silk Cake (Plant-Based, Gluten-Free Dessert), this recipe relies on simple ingredients to create a rich texture without flour
  • Add a spoonful of yogurt or whipped cream

How to Store This Custard Cake

Store covered in the refrigerator for up to 5 days.
Serve chilled for the best texture.

More Gluten-Free Dessert Recipes to Try

  • Gluten-Free Berry Cream Bars (No-Bake, Egg-Free)
    A chilled, no-bake dessert with a creamy filling, crunchy nutty crust, and fresh berries. Easy to make and perfect for warm weather or when you want something light without turning on the oven.
  • Flourless Chocolate Ganache Mini Cake
    Rich, dense, and deeply chocolatey. This flourless mini cake is simple to make and delivers a smooth ganache finish that’s ideal when you want something small but satisfying.
  • Keto Mini Blueberry Cheesecakes
    Low-carb and packed with flavor, these mini cheesecakes combine cream cheese, lemon, and blueberries for a rich dessert that fits a keto lifestyle without feeling restrictive.
  • Gluten-Free Mini Lemon Cakes
    One of those easy, reliable recipes you can make anytime. Simple ingredients, quick prep, and a soft texture that makes it a go-to when you need a no-fuss dessert.
  • Gluten-Free Death by Chocolate Cake
    A bold, rich dessert with a chocolate truffle base and smooth mousse topping. Intense flavor, small slices go a long way, this one’s made for serious chocolate cravings.

gluten-free high-protein custard cake with fruit”

FAQ – Flourless High-Protein Custard Cake

Why did my cake rise and then deflate?
That’s part of the process. The structure sets as it cools into a custard.

How do I know it’s done baking?
The top should be lightly golden and the center should feel set. It should not deflate when gently pressed.

Can I open the oven to check it early?
No, keep the oven closed for the first 30 minutes so it rises properly.

Can I use frozen fruit?
Yes, add it straight from frozen.

When should I remove it from the pan?
Only after it’s fully chilled.

Tried this recipe?

If you enjoyed this grain-free, high-protein dessert, please leave a star rating and review! Your feedback helps others find these recipes. Be sure to FOLLOW US on FACEBOOK or, check us out on PINTEREST. And don’t forget to sign up for our newsletter. We always have something delicious coming next! 

Many thanks!

Kristina x

Nutrition Info

  • (Per Slice) Calories: 230 Protein: ~8g Carbohydrates: ~28g Fat: ~10g Sugar: ~ about 18g (depending on fruit), Fiber: ~3g (varies depending on fruit used) Sodium: ~150mg | Note: These values are estimates and can vary based on specific brands. Nutrition information is automatically calculated, so should only be used as an approximation.

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