Learn how to make traditional Castella Sponge Cake with this easy step-by-step recipe. This Japanese honey sponge cake is soft, fluffy, and perfectly moist with a delicate sweetness.

Castella Sponge Cake

Castella Sponge Cake, also known as Japanese Honey Sponge Cake, is a soft and delicate dessert known for its fine crumb and moist texture. Originally introduced to Japan by Portuguese merchants in the 16th century, Castella has become a beloved Japanese confection. Unlike typical sponge cakes, Castella uses bread flour and honey to create its signature texture and gentle sweetness.

This cake is baked slowly to achieve its golden brown top and smooth, tender interior. It is often served in rectangular slices and enjoyed with tea.

Ingredients

6 large eggs (room temperature)
1 cup granulated sugar
2 tablespoons honey
2 tablespoons warm milk
1 cup bread flour
1 teaspoon vanilla extract (optional)

Equipment Needed

8 x 8 inch square baking pan or Castella mold
Parchment paper
Electric mixer or hand mixer
Mixing bowls
Fine sieve
Spatula

Directions

Step 1: Prepare the Baking Pan

Preheat the oven to 320°F (160°C).

Line the bottom and sides of an 8 x 8 inch baking pan with parchment paper, allowing the paper to extend slightly above the edges for easy removal.

Step 2: Prepare the Honey Mixture

In a small bowl, combine the honey and warm milk. Stir until the honey dissolves completely. Set aside.

Step 3: Beat the Eggs and Sugar

Crack the eggs into a large mixing bowl.

Add the granulated sugar and beat with an electric mixer on medium-high speed for 5–7 minutes until the mixture becomes pale, thick, and tripled in volume.

The batter should fall in ribbons when the whisk is lifted.

Step 4: Add the Honey Mixture

Add the honey and milk mixture along with the vanilla extract (if using). Mix gently until fully combined.

Step 5: Add the Flour

Sift the bread flour through a fine sieve into the batter.

Fold the flour gently into the mixture using a spatula. Use slow folding motions to maintain the air in the batter.

Mix until no dry flour remains, but avoid overmixing.

Step 6: Pour and Remove Air Bubbles

Pour the batter into the prepared pan.

Tap the pan lightly on the counter several times to release any large air bubbles.

Step 7: Bake the Cake

Bake at 320°F (160°C) for 45–50 minutes.

The top should turn golden brown and a toothpick inserted into the center should come out clean.

Step 8: Remove and Cool

Remove the cake from the oven and gently drop the pan from about 6 inches above the counter to prevent shrinking.

Remove the cake from the pan and peel off the parchment paper.

Let the cake cool completely on a wire rack.

Step 9: Rest the Cake

For the best texture, wrap the cooled cake tightly in plastic wrap and let it rest at room temperature for 4–6 hours or overnight. This step helps the cake develop its signature moist texture.

Serving Suggestions

Slice the Castella cake into rectangular pieces and serve with:

Green tea
Coffee
Fresh berries
Light whipped cream

Tips for Perfect Castella Cake

Use bread flour instead of cake flour for the traditional texture.
Beat the eggs and sugar thoroughly to create a stable foam.
Fold the flour gently to avoid deflating the batter.
Allow the cake to rest after baking to improve flavor and moisture.

Storage Instructions

Store the cake wrapped in plastic wrap at room temperature for 2–3 days.
For longer storage, keep it refrigerated for up to 5 days.

Castella sponge cake