How to Make Chocolate Castella Cake: A Unique Japanese Cake

Chocolate Castella Cake offers a delightful twist on the classic Japanese Castella. With its soft, fluffy texture and rich chocolate flavor, this dessert is perfect for any occasion. Below, you'll discover a step-by-step guide to making this delicious treat, along with pro tips for achieving bakery-quality results at home.

Chocolate Castella Cake is a Japanese sponge cake infused with the deep, velvety flavor of chocolate. Similar to the traditional Castella, it boasts a moist and cotton-soft texture. The bottom layer, sprinkled with coarse sugar, adds a delightful crunch, making every bite unforgettable.

The unique ingredient here is mirin, a sweet Japanese rice wine often used in savory dishes. In this recipe, mirin enhances the cake's moisture and imparts a subtle sweetness that complements the chocolate beautifully.

The original Castella Cake, or Kasutera, was introduced to Japan by Portuguese missionaries in the 16th century. Over time, this dessert became a staple of Japanese confectionery, with regional variations emerging across the country. The chocolate version adds a modern twist to this beloved classic.

To create this delectable dessert, gather the following:

• 3 eggs (separated into whites and yolks)
• 70 g sugar
• 1 tbsp honey
• 1 tbsp mirin
• 50 g chocolate (finely chopped)
• 50 g all-purpose flour (sifted)
• 50 cc milk
• 2 tbsp coarse sugar
• 1 tbsp honey (for syrup)
• 1 tbsp water (for syrup)

Start by preheating your oven to 180°C (350°F). Line a 20 x 11.5 x 7.5 cm (7.8 x 4.5 x 2.9 inches) loaf pan with parchment paper, ensuring the edges are well-covered. Sprinkle coarse sugar evenly at the base for a signature crunch.

• Sift the flour into a bowl.
• Separate the egg whites and yolks.
• Chop the chocolate into fine pieces for melting.

Combine the chopped chocolate, milk, honey, and mirin in a heatproof bowl. Place the bowl over a simmering pot of water (bain-marie). Stir until the mixture melts and turns smooth. Set aside to cool slightly.

Whip the egg whites in a large bowl using an electric mixer. Gradually add sugar, beating until stiff peaks form. This process ensures the cake achieves its signature fluffy texture. Pro tip: Beat on high for about 3–4 minutes for the best results.

Using the same mixer, beat the egg yolks until creamy and slightly pale. Slowly incorporate the melted chocolate mixture, then gently fold in the sifted flour until well combined. The batter should be smooth and lump-free.

Fold one-third of the meringue into the yolk mixture to lighten it. Carefully repeat this process twice more, ensuring the batter remains airy. Use a spatula to scrape the sides and bottom, mixing gently until no streaks of meringue remain.

Pour the batter into the prepared loaf mold, aiming for a steady stream to avoid air pockets. Run a knife or skewer through the batter to release trapped bubbles, then gently tap the mold against the counter. Bake at 180°C (350°F) for 10 minutes, then reduce the temperature to 160°C (320°F) and bake for an additional 25 minutes.

• While baking, mix honey and water to create the syrup.

Once baked, remove the mold from the oven and lightly tap it on the counter to prevent shrinking. Allow the cake to cool enough to handle, then peel away the parchment paper. Brush the surface with honey syrup, wrap it tightly in plastic, and rest it upside down overnight. This resting period enhances the cake's flavor and texture.

Slice the cake with a moistened knife for clean, precise cuts. Pair it with ice cream, whipped cream, or dusted cocoa powder for a luxurious dessert experience.

1. Use Room-Temperature Eggs: This ensures better volume when whipping.
2. Avoid Overmixing: Gently fold the batters to maintain the cake's airy texture.
3. Let It Rest: Allowing the cake to rest overnight deepens the flavor and improves moisture.

Chocolate Castella Cake combines the best of traditional Japanese flavors with a modern chocolate twist. Its light, moist crumb and delightful crunch make it a showstopper for parties, afternoon tea, or as a thoughtful gift. Plus, it’s freezer-friendly, so you can always have a slice ready for indulgence.

Try this recipe today and savor the taste of authentic Japanese baking with a chocolaty flair!