1.

Eggs are divided into egg whites and yolk, which are put into the pot respectively. The egg white pot must be oil-free and water-free.

2.

Beat the egg yolk well, add water and salad oil and mix well.

3.

Add 20 grams of fine sugar and stir well.

4.

Sift the flour into the egg yolk paste and stir well with a spatula.

5.

Add 20 grams of fine sugar to the egg whites and beat with an egg beater until it is difficult to foam. Lift the eggbeater with a small sharp corner.

6.

Add 1 teaspoon of corn flour and continue to kill for about 1 minute.

7.

Take out the egg white, scoop half of the egg white into the egg yolk paste and stir well, then pour the stirred paste into the egg white and stir well quickly.

8.

Divide the mixed cake paste into 4 parts, add red, yellow, blue and green pigments respectively, and stir well.

9.

Put them in four paper bags and squeeze them into a square baking tray covered with oil paper. One color is next to another and squeezed into long strips.

10.

Put it in a preheated oven, 180 degrees, and bake the middle layer for about 10- 12 minutes (insert it with a toothpick and it will be cooked without sticking).

1 1.

Take out the inverted buckle and let it cool, and tear off the oily paper on the back. At this time, send some whipped cream (80g whipped cream plus 10g fine sugar), turn the cooled cake roll over and spread the cream on the cake (the side next to the oiled paper is now the back when baking, and the rolled side is the front).

12.

Spread a layer of oil paper on the bottom, roll up the cake and put it in the refrigerator for 2 hours.

13.

Slice it while eating.