▷Ingredients（375mm×240mm）:
■Swiss roll
4 egg yolks
20g unsalted butter
20g water
45g cake flour
4g cocoa powder
4 egg white
80g sugar
■Chocolate cream
40g sweet chocolate
200ml heavy cream
5g sugar
30g sweet chocolate(for topping)
pistachio
▷How to make:
1. make the roll cake batter. Add melted unsalted butter, water, flour and cocoa powder to the egg yolks in that order and mix thoroughly.
2. Add sugar to the egg whites in 3 parts to make a glossy meringue.
3. Add half of the meringue mixture to the egg yolk mixture and mix thoroughly. Add the remaining meringue and mix well.
4. Line a cake roll baking sheet with a cookie sheet, pour in the batter, and flatten the surface.
Bake in a preheated oven at 170℃ for 12 to 15 minutes. Immediately after baking, remove from the baking sheet, cover with a cookie sheet, and allow to cool.
6. Melt 40 g of sweet chocolate in a pan of simmering water, add 50 ml of cream and mix until glossy.
7. Add sugar to 150 ml of cream and beat loosely while placing the mixture in ice water to cool.
8. Remove from ice water, add the chocolate cream from step 6), and beat until stiff peaks remain.
9. Peel off the paper from the roll cake dough and cut off the dough on the far side as seen from you at an angle. Cut off the dough on the front side in a straight line. 10.
10. Spread the chocolate cream and roll the roll cake. Cover with paper and refrigerate for 1 hour.
11. Melt 30 g of sweet chocolate in boiling water, put it in a squeeze bag, and pour it over the cake rolls. Garnish with pistachios.