Honey Kasutera (Honey Castella)

Kasutera カステラ or Castella is a popular Japanese sponge cake. It is said to have been named after the Castilla Monarchy in Spain but brought into Japan by the Portuguese merchants through Nagasaki in the 16th century. Imagine the consternation of the first European traders arriving on those shores to realize that there was not a stick of butter to be found within 2,000 miles to bake with. Sugar was introduced at the same time when European trade arrived. Kasutera developed into a softer and sweeter taste. It had great staying power because it enabled the Japanese to enjoy the novelty of cakes without having to adjust to dairy products. The importance of the latter cannot be underestimated as East Asian cultures did not have dairy in their diet until the last century.

Fast forward to modern Japan. One of the most enjoyable things to do in Japan is to wander into a confectionery or the food section of large departmental store. In there you will find an amazing array of beautifully presented desserts behind glass shelves. I always have a such hard time deciding what to get as everything looks so delectable. Kasutera is usually sold in long rectangular boxes and they often beckon. They also make lovely gifts.

Honey Kasutera (Honey Castella)

Kasutera is not the cheapest confection available by far, but one can appreciate the difficulty in getting the texture just right. Store bought ones always have the right balance of lightness and taste to it. Like many things Japanese, simple things are turned into an art form. Kasutera is essentially a sponge cake raised solely by egg foam with no butter, oil, or leavening agent. The texture is even and delicate with hardly any crumbs. The top and bottom are flat and the taste is light and not overly sweet.

Traditionally, this cake is made using a wooden frame which helps the cake bake evenly. Some even make their own cardboard boxes lined with aluminum foil for that same purpose. However, it can be successfully made using a lined baking pan with a lower oven temperature. There are only 4 ingredients used in this Honey Kasutera – eggs, sugar, flour, and honey. The honey may be substituted with matcha, cocoa powder, or brown sugar for different flavors. No frosting is used on this cake. Unlike most cakes, this one is made using bread flour, giving it a slightly “bouncy” texture. Who would have thought!

This cake is not easy to make. Many have had to try it several times before succeeding. I went through many recipes myself and finally settled on this one from Yummy Workshop. She adapted and simplified the steps from a recipe found on a Youtube video here. There is also no hand beating involved. All the mixing is done with a stand mixer. The recipe calls for 5 egg yolks and 4 egg whites in a 7in x 7in pan. I halved the recipe and used just 2 egg yolks and 2 egg whites in a 7½in x 3½in (9cm x 19cm) loaf pan. I did do away with the turbinado sugar at the base of the pan. I will make the full size next time but may have to use 5 egg yolks and 5 egg whites for a regular 8in x 8in (20cm x 20cm) pan. Please note that I have not tested this out. If you choose to double my recipe and use an 8in x 8in pan, your cake may come out a little flatter. Baking time may also differ.

Honey Kasutera (Honey Castella)

Prep Time: 10 minutes

Cook Time: 45 minutes

Yield: 1 small loaf

Honey Kasutera (Honey Castella)


  • 2 egg whites at room temperature
  • 2 egg yolks at room temperature
  • 5 tbsp (70g) sugar
  • 1/3 cup (50g) bread flour, sifted
  • 1 tbsp (25g) honey diluted with 1 tbsp hot water


Line a 7½ in x 3½in (9cm x 19cm) loaf pan with aluminum foil followed by parchment paper. Preheat oven to 325°F (165°C).

Place egg whites in mixing bowl and beat at high speed (speed 10*) for 30 seconds until slightly foamy. Add sugar in 2 to 3 increments until firm peaks form, about 4 minutes.

Add yolks one at a time at medium low speed (speed 4*) until well combined, about 1 minute. Add sifted bread flour and beat until just combined.

Pour in honey mixture and continue to beat for 1 minute.

Pour batter through a sieve into cake pan. Press with a spatula to help batter go through sieve. Tap pan on the counter to remove air bubbles. Using a spatula, smoothen the top of batter to remove any remaining bubbles.

Bake in preheated oven for 45 minutes or until top is evenly browned. Toothpick inserted into cake should come out clean.

Remove pan from oven and drop it from a one foot height onto the counter to prevent shrinkage.

When cake is cool enough to handle, remove from pan. Peel off parchment paper and turn it upside down onto a fresh piece of parchment paper. Wrap with plastic wrap and leave overnight at room temperature to preserve moisture in the cake and for flavor to develop.

To serve, cut off edges on three sides except the browned top with a very sharp knife. Cut into thick slices using a sawing motion and serve with a cup of tea.


*These are the Kitchen Aid Stand Mixer speed numbers.

Please refer to Neapolitan Kasutera post for the updated list of ingredients.


I am so delighted with this Honey Kasutera recipe. The texture was very fine and smooth and the cake was light and fluffy. It went fast and I regretted not having made the full 8in x 8in size. There was a wee bit of shrinkage and I am not sure if that was caused by lining the pan with the second layer of parchment paper. It did release the cake very easily though. However, I still think it was a great success! I have been bitten by the kasutera bug. Do stay tuned for the matcha and chocolate versions. :)

Honey Kasutera (Honey Castella)

Enjoy…..and have a wonderful day! 8)