Add 45g of sugar to 190ml of animal whipped cream about 4 times and mix until firm.
(You can make tiramisu using the remaining filling.). The larger the amount, the longer it takes, so you can set the standard with 60ml of whipped cream and 15g of sugar.)

Add 160g of mascarpone cheese and mix again with a whisk. (50g of cheese based on 60g of whipped cream) Seal the finished filling and store it in the refrigerator.

Sift 100g of flour and prepare it.

Sift 20g of unsweetened cocoa and prepare it.

Sift the prepared flour and mix with cocoa powder.

Prepare 4 egg yolks and add 50g of sugar to the same bowl.

Mix the yolk and sugar until smooth.

Please prepare 50g of sugar separately.

Break the egg and pour 50g of sugar into 4 separate whites, about 4 times, mixing until firm to make meringue.

Add meringue to the white yolk.

Gently mix the yolk and meringue with a silicone spatula.

Sift the flour and cocoa powder back into the dough. Preheat the air fryer/oven to 180 degrees.

You can see the well-mixed cocoa powder and flour.

Now mix well with a silicone spatula until no powder is visible.

Place paper foil in brownie mold and pour batter.

Bake in a preheated oven/air fryer for about 15 minutes.
It's as fluffy as Castella, where it goes in for a moment when you press it lightly with your hand and then hugs it up within a second.

If the bread sheet is high, divide it in half.

Remove the sealed filling from the refrigerator and apply it to the cake sheet divided in half. If you apply it to the edges, it may come out, so please leave the edges.

Roll on paper foil, roll the foil on both ends, or tie it with a string such as a rubber band to fix it. If you fix it with a rubber band and fix it again with a coffee sleeve, the shape will be better.
Place the fixed bread in the refrigerator for one day.

After a day, remove the shaped cake from the refrigerator.

Cut each end of the cake and about a third of the cake's body. (If you don't cut both ends, the shape isn't pretty.)

The cut bread is shaped roughly.

Melt 100g of chocolate in a medium hot water to make ganache.

Be careful not to get water in the chocolate.

Prepare 100g of whipped cream to make ganache

Bring the whipped cream to a boil over low heat.

Pour whipped cream over the medium-heated chocolate.

Mix whipped cream and chocolate to make ganache.

Roughly spread the ganache on the bread and scratch it with a fork to enhance the log texture. At this time, apply a lot of ganache to the seam of the bread for better adhesion.

Depending on your preference, you can decorate it with blueberries, sugar powder, etc.