Low-Carb Blueberry Lemon Cake

A beautifully decorated blueberry keto cake featuring a light frosting, fresh blueberries, and a low-carb, sugar-free recipe suitable for ketogenic diets.

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Blueberry Lemon Cake is a light, refreshing layered dessert made with lemon sponge, blueberry mascarpone frosting, and a bright blueberry jelly center. Elegant, creamy, and perfect for warm-weather entertaining.

Prep Time40

Cook Time40

chill time5

Total Time6 20

Course: Dessert

Cuisine: American

Keyword: almond flour cake, blueberry lemon cake, blueberry mascarpone frosting, sugar-free cake

Servings: slices

Calories: 411kcal

Author: Chef Jenn

Ingredients

Sponge Cake

5 egg whites
¼ teaspoon cream of tartar
5 egg yolks
¼ cup Lakanto Golden sugar substitute
2 tablespoons lemon juice
lemon zest
1¼ cups almond flour

Blueberry Frosting

1⅓ cups mascarpone
8 tablespoons erythritol powder
½ teaspoon stevia powder
½ cup heavy whipping cream
¾ cup blueberries

Blueberry Jelly

1 cup blueberries
½ cup water
½ teaspoon stevia powder
1 teaspoon lemon juice
2 tablespoons gelatin powder

Instructions

Preheat the oven to 350°F (180°C). Line a 9-inch springform pan with parchment on the bottom and sides.
Add the egg whites and cream of tartar to a stand mixer. Whip on high until medium-stiff peaks form, stopping before the whites become dry.
In a separate bowl, beat the egg yolks and Lakanto for 2 to 3 minutes until pale and creamy. Add the lemon juice and zest and mix well, then stir in the almond flour.
Add one-quarter of the whipped egg whites to the batter and mix gently with a spatula to loosen it. Fold in the remaining egg whites in two additions, keeping the batter light and airy.
Pour the batter into the prepared pan, spread evenly, and tap the pan lightly to release air bubbles. Bake for about 35 minutes, until set. Cool completely in the pan, then remove and slice the cake horizontally into three even layers.
To make the frosting, mix the mascarpone, erythritol, and stevia until smooth. Slowly add the heavy cream and beat on medium-high for about 3 minutes until thickened. Add the blueberries and mix on high speed until the frosting turns purple. Refrigerate for at least 2 hours then transfer to a piping bag fit with a large round hole.
To make the jelly, combine all jelly ingredients in a small saucepan and simmer for about 5 minutes. Blend briefly with an immersion blender until smooth, then refrigerate for at least 2 hours to set.
To assemble, place one sponge layer on a cake stand and frost the top. Pipe a frosting border around the edge and fill with half of the blueberry jelly. Add the second layer and repeat, then top with the final layer and frost the entire cake. Decorate as desired and keep refrigerated until serving.

Notes

Chef Jenn’s Tips

A springform pan makes removing the sponge much easier without tearing the layers.
Chill both the frosting and jelly fully before assembling so the layers stay clean and defined.
Use a piping bag to create a frosting “dam” so the jelly doesn’t leak out between layers.
Keep the cake refrigerated until serving since the mascarpone frosting softens quickly at room temperature.

Nutrition