Uploaded June 2023 | Updated September 2026, 1 week ago

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*Drawing batter*
15g water
8g oil
20g cake flour
1 egg yolk
➡️ add all above and mix well
➡️ split batter into two equal part
➡️ one added with 1tsp cake flour
➡️ one added with 1/2 dark cocoa powder
1 egg white
1/2tsp corn flour
➡️ beat the egg white with cornflour till firm peak
➡️ take half meringue to combine with plain yolk batter
➡️ take the balance half meringue to combine with cocoa batter
➡️ draw black piano key and bake at 170C for 1min
➡️ remove tray from oven and draw the white piano key, bake at 170C for 1min
➡️ set aside and prepare main batter
*Main batter*
7g cocoa + 15g hot water
40g milk
40g oil
60g cake flour
4 yolk
4 whites
55g sugar
5g lemon
Method
➡️ add milk and oil, mix well
➡️ add cake flour and mix well
➡️ add cocoa paste and mix well
➡️ add yolks and mix well
➡️ set aside
➡️ Beat egg whites with lemon juice with high speed
➡️ add 1/3 sugar when big bubbles seen
➡️ continue beating and add 1/3 sugar when meringue form finer bubbles
➡️ add last 1/3 sugar when meringue shows some line while beating
➡️ beat meringue to firm/medium peak
➡️ fold 1/3 of meringue to the yolk batter
➡️ pour back the batter to the balance meringue and fold well
➡️ Pour the batter gently on top of the piano batter. Spread gently
➡️ Bake at 170C for 18-20mins
➡️ After baked, cool cake (with piano key facing up) on rack completely (cover loosely with parchment paper)
➡️ Spread your favourite filling and roll up
Tray size - 11x11” (28x28cm)