2. Sieve the powder and salt, pour in 1 and stir gently;
3. Add the egg yolks to 2 one by one and stir well.
4. Beat the egg white into coarse bubbles with an egg beater, then add white vinegar twice and 50 grams of sugar three times until it is dry and foaming;
5. Add 1/3 protein into the egg yolk paste and stir well, then add 1/3 protein and stir well, then pour all the egg yolk paste into the protein and stir well from bottom to top with a spatula;
6. Pour oil paper into the baking tray, lightly drop it a few times, and enter the middle layer of the oven 160 degrees for 22 minutes.
7. After taking it out, buckle it upside down on the chopping board covered with plastic wrap, tear off the oily paper, cool it slightly, remove the hard edges around it, roll it up and shape it for 5 minutes, then put it down, completely cool it, coat it with fresh cream, roll it tightly with plastic wrap again, and slice it as needed after putting it in the refrigerator for 30 minutes.