To make the roll cake batter: Line a baking sheet with parchment paper. Preheat the oven to 170°C.

Microwave the white chocolate and milk together to melt. When melted, add the vegetable oil to mix in.

Add the sugar little by little to the egg whites. Whisk with a hand mixer to make a meringue. Be careful not to make it too hard.

Add the sieved flour little by little, mix with a spatula.

Add the meringue into Step 2's bowl.

It looks like this.

Put the mixture back to Step 4's bowl. Mix well evenly.

Pour the batter into a sheet and bake for about 12-13 minutes at 170°C.

The cake will be slightly browned after baking. Cover with plastic wrap on the top and let cool.

Whisk the heavy cream and sugar. Then add the dissolved chocolate and mix in.

Remove the wrap from the cake, place the cake on the plastic wrap.

Spread the cream on the browned side. Spread it thickly at the front and make a bit of a mound at the end.

Roll it up from the front. Place the roll with the sealed side down. Fold both ends tightly with plastic wrap, and let it cool in the fridge.

It's done! You can really taste the white chocolate. Decorate to your liking.