Honey Lemon Sponge Cake(Kastutera)

This is a riff on castella, the beloved Japanese honey sponge cake that traces back to Portuguese traders. It’s tall, springy, and finely grained, sweetened with honey and brightened with lemon.

The lift comes entirely from eggs, no butter and no baking powder. That’s why two techniques matter so much here. First, the yolks, sugar, and honey are whisked over a bowl of hot water until pale and doubled, which warms them so they whip to maximum volume.

Second, the whites are beaten separately to stiff peaks with cream of tartar, then folded in gently in thirds. Folding, not stirring, is what keeps all that hard-won air in the batter for a light, bouncy crumb.

Tapping the filled pan on the counter knocks out big air bubbles for an even, fine texture.

The result is a delicate, low-fat sponge with a honeyed aroma. Serve it plain with tea, or with fresh fruit and a little whipped cream.

Chef Tips

• Warm the yolk-and-honey mixture over hot water as you whisk; warm eggs whip to far greater volume.
• Fold the stiff egg whites in gently, in thirds, so you don’t deflate the batter.
• Tap the filled pan on the counter before baking to release large air bubbles for a fine, even crumb.

Variations

• Use orange or yuzu extract in place of lemon.
• Brush the warm cake with a honey glaze for extra moisture and shine.
• Add a teaspoon of matcha to the flour for a green tea castella.