Castella (カステラ, Kasutera)

Ingredients

Equipment Needed

• •20 cm square castella wooden frame, or an 8-inch square cake pan double-lined with parchment
• •Stand mixer or hand mixer
• •Fine-mesh sieve
• •Instant-read thermometer
• •Bamboo skewer

Instructions

1. 1

   Line the pan

   Heat the oven to 325 F / 160 C. Line an 8-inch (20 cm) square pan with parchment so the paper rises at least 2 inches above the sides. Do not butter the paper. Fat makes the batter slip before the egg foam has set, and this cake rises on that foam alone.

   A wooden castella frame insulates the sides and gives the most even crumb. A metal pan works if you give it a tall parchment wall and set it on a baking sheet.
2. 2

   Loosen the honey

   Stir the honey, mizuame if using, and warm water together until smooth. If the mizuame is stiff, set the cup in warm water for a minute. Loosening it now lets it disappear into the batter later; poured in thick, it sinks and leaves sweet pockets where you don't want them.

3. 3

   Warm the eggs

   Put the eggs and sugar in the bowl of a stand mixer or a large heatproof bowl. Set it over warm water and whisk by hand until the sugar dissolves and the mixture feels just warmer than your hand, about 38 C to 40 C. Warm eggs stretch into a stronger foam. Hot eggs start to cook, and then the cake has lost before it has begun.

4. 4

   Beat the ribbon

   Beat on high speed for 8 to 10 minutes, until the mixture is pale, thick, and falls from the whisk in a ribbon that rests on the surface for a few seconds before sinking. Lower the speed and beat 2 minutes more. The fast beating builds the lift; the slow beating tightens the bubbles so the crumb bakes fine instead of full of holes.

   Castella has no baking powder. The air you beat into the eggs is the leavening, so this is the step that decides the cake.
5. 5

   Add flour

   Drizzle in the honey mixture on low speed. Sift the bread flour over the batter in three additions, folding each one in from the bottom before adding the next. When no dry flour shows, mix on the lowest speed for 30 to 45 seconds. The strong flour is intentional: it gives Castella its close, springy bite, but it needs enough mixing to hydrate properly.

6. 6

   Cut bubbles

   Scatter the zarame evenly over the lined bottom of the pan. Pour in the batter from a little height in one steady stream, then draw a bamboo skewer through it in tight zigzags all the way to the corners. Tap the pan twice. You are breaking the large bubbles that make tunnels, not punishing the small bubbles that make the cake rise.

7. 7

   Bake deeply

   Bake for 10 minutes at 325 F / 160 C, then lower the oven to 300 F / 150 C and bake 40 to 45 minutes more. The top should be an even deep amber and spring back slowly when touched; a skewer should come out without wet batter. If the top darkens too fast, lay a loose sheet of parchment over it after the first 35 minutes. Pull it pale and the center tastes eggy and damp; bake it hard and the crumb dries before the overnight rest can do its work.

8. 8

   Wrap warm

   Take the pan from the oven and drop it once from 4 or 5 inches onto a folded towel. It sounds more dramatic than it is; the small shock helps keep the center from sinking. Let the cake stand 8 minutes, lift it out by the parchment, peel away the side paper, and turn it top-side down onto clean parchment. When it is warm but no longer hot, wrap it tightly in parchment and then plastic wrap.

9. 9

   Rest and slice

   Rest the wrapped cake overnight in the refrigerator. This is not waiting for ceremony. The moisture evens out, the honey settles into the crumb, and the zarame softens just enough while keeping its quiet crunch. The next day, bring it to room temperature, trim the edges cleanly, and cut thick slices with a serrated knife.

Chef Tips

• •Use bread flour, not cake flour. Cake flour gives softness, but Castella wants a close, elastic crumb that pushes back gently when you bite it.
• •Zarame is worth finding. Demerara or turbinado sugar can stand in, but they melt differently and give a softer base. Say so plainly and the cake remains honest.
• •Do not skip the overnight rest. The fresh cake will smell wonderful, and it will still be less than itself. Tomorrow's slice is the one to judge.
• •Trim the browned edges before serving for the clean Nagasaki look. Keep the trimmings for the cook. This is not waste, merely a private tax.

Advance Preparation

• •Castella should be baked at least one day ahead. Wrapped tightly, it keeps 3 days refrigerated; bring it to room temperature before slicing.
• •The pan can be lined and the flour sifted earlier in the day. Scatter the zarame only when the batter is ready so the crystals stay dry and distinct.
• •For longer keeping, wrap the whole rested cake tightly and freeze up to 1 month. Thaw it still wrapped so the surface stays moist.

Frequently Asked Questions

Nutrition Information

1 serving (about 72g)