Position 7 sheets of newspaper on top of one another.
Lift the up right corner, bring to the side in front of you and fold (make a triangle).
Cut off the rectangle on the left side to make a square (still folded into a triangle at this point in the photo here).
Open up the triangle into a square and draw two 17 cm lines at every corner like shown above. Cut along the red line with scissors and fold along the black line. Do the same for the rest of the corners.
After that you can obtain this shape like a windmill with 4 "wings".
Fold the wings towards the center first and then fold the wings in half outwards to make the sides.
Partially over-lay a wing with a neighbouring wing and secure with a stapler to make a box.
Line the box with baking sheet (I used reusable baking paper in the photo).
Sprinkle brown sugar crystals on the bottom. Pre-heat the oven to 355°F/180°C.
Beat in 8 eggs in a bowl.
Whisk at a low speed with a hand mixer for 10 minutes.
Divide the sugar into 3 batches to the eggs. Continue to whisk at high speed until pale.
Add the mizuame syrup (or a mixture of milk and honey).
Mix the flour into the batter in three separates batches. Whisk until thick.
Pour the batter into the prepared mold and gently get rid of any bubbles inside the batter.
Bake at 355°F/180°C for 12 minutes, then reduce the heat to 30°0F/150°C to bake for a further 60 minutes.
Story Behind this Recipe
When I lived in corporate housing, one of my coworkers shared this recipe with me. I have many good memories of making this castella for school gatherings and fairs.
Leave the castella to rest overnight for a very moist and rich sponge!