Castella cake is a Japanese confectionary staple based on the Portuguese bolo de Castela (or cake from Castile). Originally brought to Nagasaki by Portuguese merchants in the 16th century, it has changed over time to be uniquely its own type of wagashi (or traditional Japanese sweet). Castella is classified as a sponge cake with just four ingredients: eggs, sugar, mizuame and flour. Mizuame is a malt sweetener that gives the cake its distinctive sheen. The cake is typically baked in rectangular pans and served in thick slices, with its signature color being a deep yellow from the inclusion of egg yolks. The addition of matcha powder adds color and an earthy, sweet nutty flavor. Often, the cake is served with trimmed sides, but you can skip that step if you prefer. There is also a Taiwanese adaption of castella cake that is more fluffy and spongy, versus the firm-yet-moist version from Japan. It typically calls for egg whites to be whipped, then folded into the base, whereas most Japanese castella recipes will call for whole eggs to be whipped before adding the other ingredients., May 2022


Credit: Keiko Oikawa

Recipe Summary

15 mins
9 hrs


Ingredient Checklist


Instructions Checklist
  • Preheat oven to 325°F. Coat 2 loaf pans (8 1/2- by-4 1/2-inch) with cooking spray and line with parchment paper, leaving a 2-inch overhang on two opposite sides.

  • Place eggs and sugar in the bowl of a stand mixer fitted with a whisk attachment; beat on medium-low speed until tripled in size and stable, about 10 minutes.

  • Combine mizuame and hot water in a small bowl; whisk until well dissolved. Reduce mixer speed to low and slowly add in the mizuame mixture, beating until just incorporated, about 30 seconds.

  • Combine flour and matcha in a medium bowl. Whisk thoroughly to aerate and break up any clumps. In three batches, add the flour mixture to the mixture in the mixer bowl; beat on low speed, waiting until thoroughly combined before adding more, about 1 minute.

  • Divide the batter evenly between the prepared pans. Lift each pan a few inches above the work surface and drop it down to dissipate any bubbles in the batter. Using a chopstick, draw a zigzag shape through the batter to remove any remaining bubbles. Bake until a tester inserted into the middle of the cake comes out clean and the top is a deep brown color, 45 to 50 minutes.

  • Remove the cakes from the pans using the parchment overhang and place on plastic wrap. Wrap tightly to seal in moisture; refrigerate for 8 to 12 hours. Remove and discard the plastic wrap and parchment paper before serving. Slice and serve cool or at room temperature.


2 loaf pans (8 1/2- by-4 1/2 inches); parchment paper


You can find mizuame online at Some recipes substitute honey for mizuame, but the malt sweetener gives castella cake its distinctive sheen and is the preferred choice.

Nutrition Facts

1 slice
119 calories; protein 4g; carbohydrates 22g; sugars 12g; added sugar 12g; fat 2g; saturated fat 1g; mono fat 1g; poly fat 1g; cholesterol 70mg; vitamin a iu 102IU; vitamin b3 niacin 1mg; vitamin d iu 15IU; folate 46mg; sodium 27mg; calcium 13mg; iron 1mg; magnesium 6mg; phosphorus 50mg; potassium 46mg; niacin equivalents 2mg; selenium 11mcg.