• Preheat the oven to 170 °C or 325 °F.
• Line the cake pan with parchment paper. Wrap the cake pan with two layers of aluminum foil. Make sure that the cake pan is fully covered to prevent water going into the pan.
• Separate egg yolks and egg whites into two separate bowls. Put the egg whites in the fridge.

To prepare Yolk Mixture:

• Whisk the egg yolks and soy milk until combined.

To prepare Scald Flour:

• In a separate bowl, sift the flour and hojicha powder. Set aside.
• In a small saucepan, heat the vegetable oil at a low temperature. Then pour the heated oil immediately into the flour mixture and quickly stirred until everything is combined and lump-free.
• Wait until the scalded flour mixture is partly cooled, and mix it into the yolk mixture until combined. Set aside.

To prepare Meringue:

• Bring out the egg white from the fridge. Whisk the egg whites at low speed, allowing small stabilizing bubbles to form. Add in the sugar (35g) gradually and whisk at medium-low speed. After you add the last part of sugar, turn to high speed until soft peak forms.
• Put 1/3 of the meringue into the yolk batter. Gently mix them until combine.
• Gently mix the batter with the remaining yolk batter, until combine.
• Pour the batter into the lined cake pan. Tap the pan lightly to get rid of any trapped air bubbles in the batter.
• Place the cake pan into another baking pan. Add about an inch of hot water to the baking pan, so it surrounds the pan. Make sure you add enough water, so it does not fully evaporate during the baking process.
• Bake for 10 minutes at 170°C. Then bake for 45 minutes at 150°C (300°F).
• Once it is done, turn off the oven and let the cake be in the oven for 5 minutes.
• Remove the cake from the pan. Ready to serve.