Keto Low-Carb Vanilla Sponge Cake
This airy sponge cake achieves remarkable lightness through carefully folded egg whites while keeping carbs minimal with coconut flour and sugar-free sweetener. The vanilla protein powder adds structure and subtle flavor, while lemon zest brightens each bite. Perfect for birthdays or special occasions when you want an elegant dessert that fits low-carb lifestyles. The key technique is gentle folding to preserve the delicate foam structure that gives this cake its characteristic bounce and tender crumb.
Ingredients
- 9 eggs, separated
- ½ tsp cream of tartar
- ½ tsp vanilla extract
- 1 tsp vanilla liquid stevia
- 1 tbsp lemon zest
- ¼ cup coconut flour
- ¼ cup vanilla protein powder
- ½ cup Swerve confectioners sugar-free sweetener
- ½ tsp baking soda
- ½ tsp salt
- 4 tbsp butter, melted and cooled
- fresh sugar-free whipped cream(optional)
- berries(optional)
Instructions
- 1
Grease an 8 inch spring form pan and preheat oven to 350 degrees
- 2
Place egg whites and cream of tartar in a stand mixer and mix until stiff peaks form, then set aside
- 3
Place yolks in another bowl and whisk with vanilla extract, liquid stevia and lemon zest
- 4
In another bowl whisk together the remaining dry ingredients
- 5
Combine the yolks and dry ingredients together until smooth
- 6
In small portions a little at a time, fold the egg whites into the yolk and flour mixture, being careful not to over mix and deflate egg whites
- 7
Drizzle the melted, cooled butter on the side of the bowl to slowly fold it into the batter
- 8
Pour batter into pan and bake 30 minutes or until golden on top and a toothpick in center comes out clean
- 9
Allow to cool completely before removing and adding optional toppings
- 10
Keep refrigerated
Tips
Cool the melted butter completely before folding to prevent deflating the egg whites and ensure the lightest texture.
Fold ingredients gently in small portions to maintain the airy structure that gives sponge cake its signature bounce.
Allow cake to cool completely before removing from pan as the structure continues to set during cooling.
Good to Know
Refrigerate covered for up to 3 days. Best served within 24 hours for optimal texture.
Can be made 1 day ahead. Cover and refrigerate, add toppings just before serving.
Serve chilled or at room temperature with fresh whipped cream and berries.
Common Mistakes
Don't overmix when folding egg whites to avoid deflating the meringue and creating a dense cake.
Ensure butter is completely cooled before adding to prevent melting the egg whites.
Substitutions
Dairy-Free Swaps
General Alternatives
FAQ
Can I make this without protein powder?
Yes, substitute with equal amount almond flour, but the texture will be slightly denser and less structured.
How do I know when egg whites have stiff peaks?
Lift the beaters - peaks should stand straight up without drooping. Don't overbeat or they become grainy.
Can I freeze this cake?
Yes, wrap tightly and freeze up to 2 months. Thaw in refrigerator overnight before serving.