Honey Castella Cake or Kasutera (Japan's authentic honey sponge cake)

Preheat the oven to 325 degrees F or 162 degrees C.

Line a loaf pan with parchment paper. Grease the pan with butter before fitting the parchment paper so that the paper sticks to the pan. Sprinkle a little sugar over the parchment paper.

Whisk the mixture of egg whites and egg yolks in a bowl over a saucepan of simmering water till the mixture becomes warm, for about 10 minutes.

Transfer the egg whites and yolk mixture in a stand mixer. Remove the feed tube and place a clean towel on top of the mixer jar. Whisk it on a high speed with sugar for 5-10 minutes till the mixture reaches the ribbon stage, where it is thick, pale and doubled in volume.

Mix hot water with honey and whisk it into the egg batter. (Be careful when using hot mixture.) Cover the mixer jar with a clean towel on top and process it at a low speed for about 1 minute till the honey completely blends with the egg mixture.

Shift the bread flour intermittently into the egg mixture to avoid lumps and fold it until its well combined.

Pour the batter into the loaf pan till it fills 2/3rd of the pan. Drop the pan on the table 2-3 times to remove any air bubbles in the batter.

Bake it in the preheated oven for 45-50 minutes on the middle rack or until the castella is richly golden brown and a toothpick inserted into the cake comes out clean.

Prepare the honey sauce by mixing two teaspoon of honey with two teaspoon of hot water. Lightly brush the honey sauce over the cake and allow the cake to cool for 10-15 minutes at room temperature.

Lay a plastic cling wrap on a table and turn the cake upside down over it. Then carefully peel off the lining paper and wrap it with the plastic cling wrap.

Refrigerate the cake for atleast 24 hours. (This allows the cake to soak the flavors and enhances its taste.)

While serving, take out the cake from the fridge. Allow it come to room temperature, then cut it into 1 inch slices using a serrated knife.

Serve the cake with a dollop of ice cream or as traditionally in Japan, enjoy it with green tea.