Ingredients
- 6 large eggs, separated
- 1/2 cup (120ml) sweetened condensed milk
- 1/4 cup (60ml) whole milk
- 1/4 cup (60ml) vegetable oil or melted butter
- 1 teaspoon vanilla extract
- 1 cup (120g) cake flour, sifted
- 1/4 teaspoon salt
- 1/4 cup (50g) granulated sugar
- 1 tablespoon honey (optional, for extra moisture)
Equipment
- 8×8 inch square pan or 9×5 inch loaf pan
- Electric mixer
- Large mixing bowls
- Fine mesh sieve
- Parchment paper
Instructions
Preparation:
- Preheat oven to 320°F (160°C). Line your pan with parchment paper, leaving overhang for easy removal.
- Prepare water bath: Place a larger pan on the bottom oven rack and fill with hot water about 1 inch deep. This creates steam for a moist cake.
Make the Batter:
- Mix wet ingredients: In a large bowl, whisk together egg yolks, condensed milk, regular milk, oil, vanilla, and honey (if using) until smooth.
- Add flour: Sift cake flour and salt directly into the wet ingredients. Whisk gently until just combined and smooth. Don’t overmix.
- Whip egg whites: In a clean bowl, whip egg whites with an electric mixer until foamy. Gradually add sugar and continue beating until soft peaks form (not stiff peaks).
- Fold together: Add 1/3 of the whipped egg whites to the batter and fold gently. Add remaining egg whites in two additions, folding carefully to maintain airiness.
Bake the Cake:
- Pour batter: Pour batter into prepared pan and gently tap to release air bubbles.
- Bake: Place on middle rack above the water bath. Bake for 45-55 minutes, until the top is golden brown and a toothpick inserted in center comes out clean.
- Cool: Remove from oven and immediately cover the top with aluminum foil to prevent over-browning. Let cool in the pan for 10 minutes.
- Remove: Lift out using parchment paper overhang and cool completely on a wire rack.
Finishing:
- Wrap and rest: For best texture, wrap the cooled cake in plastic wrap and let it rest at room temperature for 2-3 hours or overnight. This allows the cake to become even more moist and develop its characteristic texture.
Tips for Success
- Room temperature ingredients: Use eggs and milk at room temperature for better mixing
- Gentle folding: Don’t overmix when folding in egg whites to keep the cake light
- Water bath: The steam keeps the cake moist and prevents cracking
- Don’t overbake: The cake should spring back lightly when touched
- Resting time: Castella improves with time, becoming more moist and flavorful
Serving Suggestions
- Serve plain to appreciate the delicate sweetness
- Dust with powdered sugar
- Serve with fresh berries and whipped cream
- Pair with green tea or coffee
Storage
Store wrapped in plastic at room temperature for up to 3 days, or refrigerate for up to a week. The cake actually improves in texture after the first day.
Variations
- Matcha Castella: Add 2 tablespoons matcha powder to the flour
- Chocolate Castella: Replace 2 tablespoons flour with cocoa powder
- Lemon Castella: Add zest of 1 lemon and 1 tablespoon lemon juice
Prep Time: 30 minutes
Bake Time: 45-55 minutes
Total Time: 1 hour 25 minutes (plus resting time)
Serves: 8-10 pieces
