Recipe: Kasutera-Japanese Sponge Cake

KASUTERA-JAPANESE SPONGE CAKE

Kasutera is a sponge cake made of sugar, flour, eggs, and starch syrup. It is a speciality of Nagasaki Japan, but the cake is originally from Spain. The name is believed to derive from a region called Castilla. During the 16th century, a Portuguese ship came into Nagasaki, which used to be the port of Japanese commerce. The Portuguese brought the Japanese many unusual things such as guns, tobacco, and pumpkins. Kasutera was also one of the things they brought. Kasutera was able to be preserved for a long period of time so it was necessary for the sailors who were out on the sea for months. In the Edo era, it was a sweet that was precious and was served for the envoys from Korea. Later, Japanese people started making kasutera, and the cake's taste slowly changed to fit to the Japanese palate. This is the root of the kasutera in today's Japan.

Kasutera is made of natural ingredients, so its simple taste is a favorite of many Japanese people. There are now many kinds of kasutera, made with various ingredients. For example, there are kasuteras made with powdered green tea, cocoa, and also brown sugar.

1 cup plus 1 tablespoon granulated sugar
1/4 cup honey
1 teaspoon vanilla extract
1 teaspoon lemon extract
1/4 teaspoon salt
7 large eggs, separated
1 cup cake flour, sifted
1/8 teaspoon cream of tartar
1 tablespoon green tea powder or unsweetened cocoa powder (optional-if using omit the lemon extract)

Preheat oven to 325 degrees F (160 C). Use parchment to line the bottom of a 10-inch tube pan, preferably with a removable bottom or 2 (8 x 4-inch) loaf pans. Grease the parchment.

In a large bowl, whisk 1 cup sugar, honey, vanilla, lemon extract, and salt into egg yolks. Place bowl in a large pan of hot water. With an electric mixer, beat about 5 minutes on medium-high speed until pale yellow and doubled in volume. Gently fold in sifted flour.

Wash beaters. In a large bowl, beat egg whites in electric mixer on a low speed 1 minute, increasing speed to medium-high. When foamy, sprinkle in 1 tablespoon sugar and cream of tartar. Beat until stiff but not dry. With a spatula, fold the egg whites in thirds. Pour batter into pan. Tap gently on the counter to remove air bubbles.

Bake on middle rack of oven 35 to 45 minutes or until golden brown. When done, cake sides will pull away from pan slightly; top will be flat and feel spongy when pressed with finger. Cool 20 minutes. Run a small knife between edge of cake and pan. Remove from pan carefully. Pull off parchment and cool completey. Serve or store airtight.

Source: Japanese Cooking for the American Table by Susan Fuller Slack