Fluffy Castella Sponge Cake
This fluffy Castella sponge cake is the definition of soft perfection. Each slice has a delicate bounce, a smooth, fine crumb, and a light sweetness that melts on the tongue. It’s an elegant yet simple cake that needs no frosting or filling—just pure, pillowy satisfaction.
Why You’ll Love This Castella Cake
Originating from Japan and inspired by European sponge cakes, Castella (Kasutera) is known for its unique texture and gentle sweetness.
- Feather-light texture: Airy and soft thanks to whipped egg whites
- Moist and tender: Made with oil and milk instead of heavy fats
- Balanced sweetness: Light and delicate, never overwhelming
- Golden top: Naturally caramelized with no extra toppings needed
- Elegant simplicity: Perfect for tea time or light desserts
Ingredients
- 6 egg whites
- 6 egg yolks
- 85 g sugar (caster or superfine)
- 80 ml vegetable oil
- 90 g cake flour
- 70 ml milk
- ¼ tsp salt
Step-by-Step Instructions
1. Whip the Meringue
Beat egg whites until foamy. Gradually add sugar and whip until stiff, glossy peaks form.
2. Prepare the Batter Base
Warm the oil slightly (do not overheat).
Add sifted flour and salt, mixing until smooth.
Stir in egg yolks and milk until you get a silky batter.
3. Fold in the Meringue
Gently mix one-third of the meringue into the batter.
Fold in the remaining meringue in two additions, keeping the mixture light and airy.
4. Pour and Tap
Pour into a parchment-lined pan (do not grease sides).
Tap the pan lightly to remove air bubbles.
5. Water Bath Baking
Place the cake pan inside a larger pan filled halfway with hot water.
Bake at 150°C (300°F) for about 60 minutes, until set and lightly golden.
6. Cool and Slice
Tap the pan gently after baking to release steam.
Cool completely before slicing with a serrated knife.
Pro Tips for Success
- Use room temperature eggs for better volume
- Sift flour to avoid lumps and ensure a smooth crumb
- Fold gently—never stir aggressively
- Bake low and slow to prevent cracks
- Avoid overheating the oil
Flavor Variations
- Matcha: Add 1 tsp matcha powder to the flour
- Honey: Replace 1 tbsp sugar with honey
- Lemon: Add lemon zest for brightness
- Jam Layer: Slice and spread a thin layer of jam
- Mini Cakes: Bake in smaller molds for individual portions
Serving Suggestions
- Pair with tea or coffee
- Serve with fresh berries and whipped cream
- Add a light fruit compote for extra flavor
- Enjoy plain for its natural softness
Storage Tips
- Room temperature: Up to 3 days, wrapped היטghtly
- Refrigerator: Up to 5 days (bring to room temp before serving)
- Freezer: Slice, wrap, and freeze for up to 1 month
FAQs
Why is my cake not fluffy?
Overmixing or deflating the meringue can reduce airiness. Fold gently and use properly whipped egg whites.
Can I use all-purpose flour?
Yes, but cake flour gives a softer, lighter texture.
Do I need a water bath?
Yes. It ensures even baking, prevents cracking, and keeps the cake moist.
Why did my cake collapse?
It may be underbaked or cooled too quickly. Let it cool gradually in the pan.
Can I make it dairy-free?
Yes, substitute milk with plant-based alternatives like almond or soy milk.
This Castella sponge cake is soft, light, and beautifully simple—a timeless recipe that proves less truly can be more.
