Head into an Asian bakery and you will see baskets full of small Castella cakes. They are spongy and a tiny bit dry, so that it takes a few minutes to melt in your mouth.
Castella is basically a Japanese honey spongecake. It has no butter in it, but rather gets its richness from the large amount of eggs.
6 large eggs, at room temperature
1 cup (218 g) sugar
1 cup + 2½ Tbsp (200 g) bread flour
5 Tbsp. honey + 2 ½ Tbsp. warm water
2 Tbsp. honey + 1 Tbsp. warm water for the glaze
Preheat oven to 320F. Whisk together the 5 Tbsp. honey + 2 ½ Tbsp. warm water . Set aside.
Sift the bread flour with the sifter or a fine-meshed strainer twice.
Fit the mixer with the whisk attachment. Crack eggs into the bowl and vigorously whisk until combined and frothy. Add the sugar and beat on high speed (Speed 10) for 5 minutes. The volume of the beaten eggs will increase about 4 times. The texture will be thick and the color will be pale yellow. When you stop the mixer and lift the whisk attachment, the mixture should fall in ribbons. Add the honey mixture into the egg mixture and whisk on low speed (Speed 2) until combined, about 30 seconds.
Add the bread flour in three additions: add ⅓ of the bread flour and whisk on low speed (Speed 2) for 15 seconds, then add more flour and whisk for 15 seconds. Add the last remaining portion and whisk until just combined for about 1 minute. Do not overmix.
Spray the loaf pans with oil and spread out evenly with pastry brush. Put the parchment paper in the pans and make sure the paper sticks to the pans. If not, add oil and spread out evenly with a brush.
Pour the batter into the pans. Using a skewer, draw a zigzag line to remove the air bubbles in the batter. Level batter in each pan by holding pan 2 inches above counter dropping it flat onto counter. Do this several times to release air bubbles.
Bake at 320F on middle rack of oven for 35- 40 minutes or until golden brown and a skewer inserted in the center comes out clean. When done, cake sides will pull away from pan slightly; top will be flat and feel spongy when pressed with finger.
Mix the honey and warm water in a bowl for the glaze and brush on top of the cakes.
Place a sheet of plastic wrap on the counter top. Take out the cake from the pan to the plastic wrap, top facing down. Gently peel off parchment paper. Immediately wrap the cake with plastic wrap to keep the moisture and store in the refrigerator overnight (at least 12 hours), keeping the top side facing down. This will help the cake have a good texture.
To serve, slice off the sides of the cake with a sharp bread knife and cut into 1 inch thick slices. Serve at room temperature.
To store, wrap individual pieces with plastic wrap and freeze up to a month or refrigerate up to 5 days.