Savory LifeRECIPES

Castella Cake Perth: Soft Japanese Sponge Recipe

Updated November 7, 2026

Total time
3 hr 20 min
prep 25 min · cook 1 hr 10 min
Serves
8
portions as written

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Castella Cake Perth: Soft Japanese Sponge Recipe

Castella cake is a soft, moist Japanese sponge cake made from just four ingredients—eggs, sugar, flour, and honey—baked in a loaf pan and cut into neat slices. It has a dense, velvety crumb and a gentle sweetness, making it a favorite in Perth’s Japanese bakeries. This recipe recreates that bakery-style texture at home using a simple water bath and a few careful techniques, so you get the signature glossy top and tender interior every time.

Ingredients

  • 6 large eggs (about 300 g / 10.5 oz), cold
  • 1 cup (200 g) caster sugar
  • 2 tbsp (40 g) honey
  • 1 cup (120 g) bread flour, sifted
  • 1 tbsp (15 ml) whole milk (optional, for extra moisture)
  • 2 tbsp (30 ml) hot water (for the water bath)
  • Butter or oil for greasing the pan
  • Parchment paper

Instructions

  1. Preheat your oven to 320°F (160°C). Grease a 9×5-inch (23×13 cm) loaf pan and line it with parchment paper, letting the paper overhang the edges for easy lifting.
  2. Fill a large roasting pan or baking dish with about 1 inch (2.5 cm) of hot water and place it on the oven rack. This will be the water bath for baking.
  3. In a large mixing bowl, combine the eggs, caster sugar, and honey. Place the bowl over a pot of simmering water (make sure the bottom doesn’t touch the water) and whisk gently until the sugar dissolves and the mixture is lukewarm, about 3-4 minutes. This step helps the eggs whip to a thicker ribbon stage.
  4. Remove the bowl from the heat and beat the egg mixture with an electric mixer on high speed for 8-10 minutes, until it is pale, thick, and tripled in volume. When you lift the whisk, the batter should fall in a thick ribbon that slowly dissolves on the surface.
  5. Reduce the mixer speed to low and beat for 2 more minutes to stabilize the bubbles. This makes the crumb finer.
  6. Sift the bread flour into the batter in three additions. Use a spatula to fold gently after each addition, cutting through the center and scraping the sides until no streaks of flour remain. Be careful not to deflate the batter.
  7. If using milk, gently fold it in now along with the last addition of flour.
  8. Pour the batter into the prepared loaf pan. Tap the pan on the counter a few times to release large air bubbles.
  9. Place the loaf pan into the water bath in the oven. Bake for 60-70 minutes, or until the top is deep golden brown and a skewer inserted into the center comes out clean. The internal temperature of the cake should read 200°F (93°C) for a fully set crumb.
  10. Turn off the oven and leave the cake inside with the door slightly ajar for 10 minutes. This helps prevent the top from sinking.
  11. Remove the cake from the oven and let it cool in the pan on a wire rack for 15 minutes. Then lift it out using the parchment paper, peel off the paper, and let it cool completely on the rack.
  12. Once cool, wrap the cake tightly in plastic wrap and refrigerate for at least 2 hours (or overnight) before slicing. This makes it easier to cut clean slices.

Tips

  • Use bread flour: Bread flour has more protein than all-purpose, giving the cake its characteristic chewy, dense texture. If you only have all-purpose, use the same amount, but the crumb will be slightly lighter.
  • Don’t skip the water bath: The water bath keeps the oven moist and prevents the cake from drying out or cracking on top. Make sure the water is hot when you put the pan in.
  • Chill before slicing: Castella is notoriously sticky and soft; chilling it for a few hours firms the crumb so you can cut neat, even slices with a serrated knife.
  • Common mistake: Over-folding the flour will deflate the batter and make the cake dense and heavy. Fold just until no flour is visible, even if a few lumps remain.

Serving Suggestions

Serve castella cake as a snack with green tea or coffee. It’s also wonderful lightly toasted and spread with butter or honey. For a dessert, pair it with fresh berries and a dollop of whipped cream. In Perth, it’s often enjoyed as a simple afternoon treat with a matcha latte.

Variations

  • Matcha Castella: Replace 1 tablespoon (8 g) of the bread flour with matcha powder and sift together. This gives a beautiful green color and earthy flavor.
  • Chocolate Castella: Replace 2 tablespoons (16 g) of flour with unsweetened cocoa powder.
  • Honey-less version: If you prefer a less sweet cake, omit the honey and add an extra tablespoon of sugar. The texture will be slightly less moist.

Storage and Reheating

Store castella cake wrapped in plastic wrap in the refrigerator for up to 5 days. It actually improves in flavor and moisture after a day. To freeze, wrap tightly in plastic and then foil, and freeze for up to 3 months. Thaw in the refrigerator overnight. To serve warm, microwave a slice for 10-15 seconds, or toast lightly.

Frequently Asked Questions

Why did my cake sink in the middle? This usually happens if the batter was under-whipped or over-folded, causing too much air to escape. Make sure the egg mixture reaches a thick ribbon stage and fold gently. Also, avoid opening the oven door during baking.

Can I use all-purpose flour instead of bread flour? Yes, but the texture will be less chewy and more cake-like. The cake will still be delicious, just slightly different from traditional castella.

Why is my cake too dense? Over-mixing the batter after adding flour is the most common cause. Fold only until the flour disappears. Also, make sure your eggs are whipped to the correct volume—this takes time, so don’t rush.

Do I need to use a water bath? It’s highly recommended. The water bath regulates temperature and adds steam, which keeps the cake moist and prevents cracks. Without it, the cake may dry out.

Can I make this without honey? Yes, you can substitute the honey with an equal amount of golden syrup or just omit it and add an extra tablespoon of sugar. The flavor will be less complex, but the cake will still work.

How do I get a perfectly flat top? Some bakers trim the top after cooling, but to prevent a dome, ensure your oven isn’t too hot and don’t overbake. The 10-minute rest in the oven with the door ajar also helps the top settle.

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Safety notes: safe minimum internal temperatures from USDA FSIS; raw and undercooked fish guidance from the U.S. FDA. Food safety notes

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