Fluffy Castella Sponge Cake – Soft, Moist & Perfectly Sweet
If you’ve ever tried a traditional Japanese Castella sponge cake (Kasutera), you know it’s unlike any other sponge cake. With its delicate, fine crumb and soft, moist texture, Castella cake strikes the perfect balance—it’s lighter than butter or pound cakes but has a tighter, more refined structure than a classic sponge. Originally introduced to Japan by Portuguese merchants in the 16th century, this cake has become a beloved dessert across Asia and beyond.
The beauty of Castella lies in its simplicity. With just a handful of ingredients—eggs, sugar, flour, oil, and milk—you can create a cake that’s fluffy, subtly sweet, and irresistibly tender. Best of all, this recipe is beginner-friendly and doesn’t require fancy equipment beyond a hand mixer.
Whether you’re baking for a special occasion, afternoon tea, or simply want to enjoy a slice of soft, golden sponge with your coffee, this Fluffy Castella Sponge Cake will be a new favorite in your kitchen.
Why You’ll Love This Recipe
✔ Soft & fluffy – A melt-in-your-mouth texture that feels light but satisfying.
✔ Simple ingredients – Made with pantry basics you already have.
✔ Beautifully golden – A cake that looks as good as it tastes.
✔ Perfectly sweet – Not too heavy, just the right amount of sweetness.
✔ Great for any occasion – Afternoon tea, birthdays, or a simple family dessert.
Ingredients
- 6 egg whites
- 6 egg yolks
- 85 g sugar
- 80 ml vegetable oil
- 90 g cake flour (or sponge flour)
- 70 ml milk
- 1/4 tsp salt
Step-by-Step Instructions
- Prepare your pan – Line a loaf pan or square baking tin with parchment paper. Preheat the oven to 320°F (160°C).
- Whisk egg yolks – In a mixing bowl, beat egg yolks with half of the sugar until pale and creamy. Slowly add vegetable oil, milk, and salt, whisking until smooth. Sift in the cake flour and gently fold until fully incorporated.
- Whip egg whites – In a separate bowl, beat egg whites until frothy. Gradually add the remaining sugar and continue beating until stiff peaks form. This step is key for the cake’s light, airy texture.
- Combine mixtures – Gently fold the whipped egg whites into the egg yolk mixture in three additions. Use a spatula and fold carefully to avoid deflating the batter.
- Bake – Pour the batter into the prepared pan and tap gently to release air bubbles. Place the pan inside a larger pan filled with hot water (a water bath) to ensure even baking. Bake for 40–50 minutes, or until the cake is golden and a skewer inserted comes out clean.
- Cool & serve – Once baked, remove from the oven and let it cool slightly before removing from the pan. Slice into neat portions and enjoy warm or at room temperature.
Tips for the Perfect Castella Sponge Cake
- Whip egg whites properly – They should be glossy with stiff peaks to help the cake rise.
- Fold gently – Overmixing will deflate the batter and create a dense cake.
- Use cake flour – It gives a softer, finer crumb than all-purpose flour.
- Bake in a water bath – This keeps the cake moist and prevents cracking.
- Rest before slicing – Let the cake sit for a few hours for the texture to set beautifully.
Variations & Serving Ideas
- Honey Castella – Add 1–2 tablespoons of honey for a richer flavor.
- Matcha Castella – Mix in 1 tablespoon of matcha powder for a green tea twist.
- Cocoa Castella – Swap 1 tablespoon of flour for cocoa powder.
- Layered Cake – Slice in half and spread with whipped cream or fruit preserves.
How to Store Castella Sponge Cake
- Room Temperature – Wrap tightly in plastic wrap and store for up to 3 days.
- Refrigerator – Keeps well for up to 1 week, but let it come to room temp before serving.
- Freezer – Wrap slices individually and freeze for up to 2 months.
Final Thoughts
This Fluffy Castella Sponge Cake is proof that simplicity is often the key to perfection. With just a few ingredients, you can create a cake that’s light, soft, and beautifully golden. Whether you enjoy it plain, paired with tea, or flavored with honey or matcha, this cake will always impress.
Once you try this recipe, you’ll see why Castella has stood the test of time for centuries. It’s delicate, elegant, and absolutely irresistible. Bake it once, and you’ll want to make it again and again. 🍰✨
