50g granulated sugar
46g cake flour
32g vegetable oil
3g lemon juice
Red bean paste or sweetened red beans
- Separate the eggs. Mix vegetable oil and milk until well combined. Add in cake flour, mix until smooth. Add in 4 egg yolks, mix until smooth. Add in some vanilla extract (optional).
- Add granulated sugar and lemon juice into the egg white, and use a hand mixer to beat until it forms soft peaks. Take a scoop of whipped egg white to mix with the batter until just combined. Pour all the batter back into the whipped egg white, mix until just combined.
- Put the batter into a piping bag with piping tip. Pipe the batter into the lined baking tray (28*28cm). Preheat the oven to 302℉(150℃) and bake for 26 minutes.
- Let the cake cool down on the cooling rack first. After that, slice the cake into 4 equal pieces, spread some mayonnaise on the cake and red bean paste as its filling. Roll the cake up and serve.