1: Whip the Meringue

• In a clean, dry bowl, beat the egg whites until they become foamy.
• Gradually add sugar and continue whipping until stiff peaks form the meringue should be glossy and stable.

2: Prepare the Batter Base

• Heat the oil for 90 seconds in the microwave or gently on the stove. It should be warm but not boiling.
• Add sifted flour and salt into the warm oil and mix until smooth.
• Stir in the egg yolks and milk, mixing until you have a silky, lump free batter.

3: Fold in the Meringue

• Take one third of the meringue and gently mix it into the batter to loosen it.
• Then, fold in the remaining meringue in two more additions, using a spatula and gentle motions to keep the batter airy.

4: Pour and Tap

• Pour the batter into a parchment lined square or loaf tin (avoid greasing the sides).
• Tap the tin on the counter several times to remove air bubbles that might cause holes during baking.

5: Water Bath Baking

• Place the cake tin inside a larger baking dish and fill the outer dish with hot water halfway up the sides.
• Bake in a preheated oven at 150°C (300°F) for about 60 minutes, or until the center springs back and a toothpick comes out clean.

6: Cool and Slice

• When done, gently bang the tin on the counter a few times to release steam and prevent shrinking.
• Let the cake cool completely in the tin, then transfer to a cutting board and slice with a serrated knife.

Pro Tips for Castella Success

Techniques That Make a Difference

This isn’t your average sponge cake the method is part of what gives Castella its signature bounce and cotton soft bite. Here are tips I follow every time:

• Use room temperature eggs: They whip better and give more volume.
• Don’t overheat the oil: Just warm enough to blend the  flour, but not hot enough to scramble the yolks.
• Always sift your flour: Even a few lumps can weigh the cake down or cause streaks.

• Fold, don’t stir: Keep your motions slow and careful to avoid deflating the airy  meringue.
• Bake low and slow: High heat causes cracking 150°C and steam creates that smooth, glossy top.

Need more steam based bakes? Check out our delicate milk custard rice  cake or the beautifully jiggly Japanese cheesecake that uses a similar water bath method for texture that wows.

Creative Castella Cake Twists

This cake is stunning in its simplicity, but here’s how I love to experiment with flavors without compromising texture:

• Matcha Castella: Add 1 teaspoon of sifted matcha powder with the flour for a subtle earthy twist.
• Honey infused: Swap out 1 tablespoon of sugar for honey for a deeper golden crust and natural sweetness.

• Lemon version: Add 1 teaspoon of lemon zest and a tiny splash of lemon juice for a bright finish.
• Layered with jam: Slice the cake horizontally and add a thin spread of fruit jam or citrus marmalade between layers.

• Mini Castella bites: Bake the batter in cupcake molds using the same water bath method for adorable, single serve treats.

Want more cake creativity? Our 3 ingredient sponge cake is perfect for fast flavor experimentation, and the Greek yogurt cake offers a rich but tangy spin on light cake recipes.

Perfect Pairings and Serving Suggestions

What to Serve With Fluffy Castella Sponge Cake