Fluffy Castella Sponge Cake

Fluffy Castella sponge cake is a Japanese classic known for its light texture, golden brown top, and subtle sweetness. Made with just a few simple ingredients—eggs, sugar, flour, and honey—this cake is incredibly soft and airy, yet rich and flavorful. It’s the kind of dessert I turn to when I want something elegant, simple, and irresistibly spongy.

Why You’ll Love This Recipe

I love this cake for its pillowy texture and the way it practically melts in my mouth. It’s not overly sweet, so it pairs perfectly with tea, coffee, or fruit. There’s no butter or oil, yet it stays moist thanks to the honey and careful baking technique. It’s also a beautiful bake that impresses with its golden top and silky crumb.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

• Large eggs (room temperature)

• Granulated sugar

• Bread flour (or all-purpose flour, sifted)

• Honey

• Warm water

• Vanilla extract (optional)

Directions

1. I preheat the oven to 320°F and line a loaf pan or square cake pan with parchment paper, letting the paper overhang slightly to help lift the cake later.

2. I warm the honey with a bit of water until smooth and set it aside to cool.

3. I separate the eggs, placing the whites in a clean mixing bowl. I beat the egg whites until foamy, then gradually add sugar while continuing to beat until stiff peaks form.

4. I lightly whisk the egg yolks and fold them gently into the meringue.

5. I sift the flour into the mixture in batches, folding gently after each addition to keep the batter airy.

6. I stir in the honey-water mixture and vanilla (if using) until fully incorporated, being careful not to deflate the batter.

7. I pour the batter into the prepared pan and tap it gently to remove air bubbles.

8. I bake for 45–55 minutes until the top is deep golden and a toothpick inserted comes out clean.

9. I let the cake cool slightly before lifting it out. For a smooth top and moist crumb, I wrap the cake in plastic wrap while still slightly warm and let it rest for several hours or overnight before slicing.

Servings and timing

This recipe yields 8–10 slices. It takes about 20 minutes to prep, 45–55 minutes to bake, and ideally rests for several hours or overnight. I usually start it in the morning and enjoy it as an afternoon or evening treat.

Variations

For extra flavor, I sometimes use matcha powder or cocoa powder in place of some flour. A citrus twist with lemon or orange zest is another favorite. If I want a more traditional Taiwanese-style castella, I bake it in a water bath for extra moisture and a delicate jiggle.

storage/reheating

I store the cake tightly wrapped at room temperature for up to 3 days. It can also be refrigerated for 4–5 days, though I let it come to room temp before serving. I don’t reheat it—Castella is best enjoyed soft and cool.

FAQs

What’s the difference between Castella and sponge cake?

Castella uses honey for sweetness and has a tighter, moister crumb than typical sponge cakes. It’s also denser but still fluffy and light.

Can I use cake flour instead of bread flour?

Yes, I can use cake flour for an even finer texture, but bread flour gives that traditional chew Castella is known for.

Why wrap the cake after baking?

Wrapping it while warm helps lock in moisture and gives the top that shiny, smooth finish. It also improves the flavor as it rests.

Can I bake this in a round cake pan?

Absolutely. I just make sure it’s not too shallow, as the batter needs room to rise. I watch the baking time closely if I change the pan.

Do I need to use a water bath?

Not always. A water bath creates a softer, moister cake, but I get great results with or without one, depending on the style I want.

Conclusion

Fluffy Castella sponge cake is a simple yet elegant dessert I love making when I want something light, sweet, and perfectly tender. With just a few ingredients and a gentle hand, I get a bakery-style treat that’s perfect for slicing, sharing, and savoring—one soft bite at a time.