Place the Kraft paper or bakery paper in the cardboard box wrapped with aluminum foil and distribute the coarse demerara sugar or coffee sugar crystals.
Lightly beat the eggs in a bowl with a hand mixer at a low speed. Add the sugar and mix.
Float the bowl in hot water and gradually heat the egg. When it begins to slightly warm up, remove the bowl and continue mixing. Turn off the burner and heat a glass of water.
Beat the egg at high speed for about 8 minutes until the color turns white, and it reaches a soft peak stage. When you lift the mixer, the rippling pattern should remain on the surface as you see here.
Dilute the honey with the heated water. Add it to the beaten egg and mix with the hand mixer for 1 more minute at high speed. Switch to low speed and mix for about another minute until it has a fine, glossy texture.
Distribute the bread flour onto the egg mixture. At medium speed, whip the mixture for about 2 minutes until it has a smooth texture again.
Drop the bowl a few times to break any air bubbles. Then, pour the batter into the square mold. Slash the batter with a spatula to remove any air bubbles.
Place the batter into a preheated conventional oven. For the first 15 minutes, bake at 170°C (340°F). Then, reduce the heat to 160°C (320°F) and bake it for about 50 more minutes. The baking temperature and time depend on the type of your oven, so adjust them accordingly.
Pierce the castella with a bamboo stick. If the stick is slightly moist, it is ready. When the stick is dry and clean, the castella has lost its moist texture. The moist texture is essential for delicious castella so avoid over-baking.
Remove the mold and drop it on the counter a few times to prevent the castella from shrinking. Place a tray covered with plastic wrap on top. Then, flip it over.
Before placing the tray onto the castella, we recommend making a cut along the corners of the Kraft paper and folding the edges outward. This will help avoid damaging the surface of the castella. Now, remove the mold.
Wrap it with 2 layers of plastic wrap crosswise, completely covering the castella. Let it sit to cool and then store the castella in the fridge for one whole day. This will make it moist and even more delicious.
Let’s serve the castella. Carefully remove the Kraft paper and slice off the edges. For each cut, wipe the knife with a dampened towel to help make a clean cut.
Cut the castella in half. Then, slice it into 3cm (1.2") pieces. Arrange the pieces onto a plate.
We will show you how to make the homemade mold for castella. This is the Kraft paper with 4 slits.
The cardboard box is wrapped with aluminum foil.
To wrap the box, carefully cover it with a long strip of aluminum foil.
Then, cover it with another aluminum strip crosswise. If you don’t have a square cake pan, try making it as shown.
All-purpose flour or cake flour can be also used but we recommend using bread flour to help create a moist and kind of gooey texture.
You can keep the castella in the fridge for 1 week or store it in the freezer for up to 1 month.
Castella goes great with green tea, coffee or black tea and it is a perfect gift for special occasions.