Preheat the oven. Preheat your oven to 350℉ and add parchment paper or spray your baking pan with cooking spray.
Melt chocolate and butter. You can use a microwave or use a bowl that can withstand high heat over a pot of steaming water on the stove to melt together butter and chocolate. Make sure it melts completely then place it aside and allow to cool down.
Whisk. Add egg whites and sugar together and whisk. (Using a mixer is best since you're trying to get these two ingredients nice and fluffy!) You want the mixture to be huge in volume so whisk away! It should take around 3-4 minutes at med-med high speed.
Combine yolks with the chocolate. To yolks, add in the cooled chocolate mixture and whisk until it's combined using a hand whisk.
Fold dry ingredients into wet. Sift all the dry ingredients - flour, cocoa, baking powder, baking soda and salt in a bowl and then fold them with yolk-chocolate mixture and ⅓ of egg whites mixture.Now add and fold egg whites mixture in the batter in two batches. Make sure that it's fluffy and smooth! Bake. Pour cake mixture onto your prepared baking sheet and bake in the oven for 10-12 minutes.
Roll the cake while it's warm. After the cake is baked all the way, let it rest for about 2 minutes in the pan, outside of the oven. Sprinkle some powdered sugar on a cutting board, then turn the cake pan upside down and place the baked cake on it. Roll the cake when it's still warm and leave it sitting to cool down all the way.
Make the whipped cream filling. As the cake is cooling, it's time to make cream filling! Whisk powdered sugar and chilled heavy cream together to form soft peaks and then fold in the cheese and vanilla.
Make chocolate ganache. Heat cream and chocolate in a microwave-safe bowl. If you break it up into pieces before melting, it makes the process much quicker. Alternatively, you can add cream to a saucepan on the stove and bring it to a bowl. Once it's boiling, add in chopped chocolate. Then stir the mixture together to allow it to combine, turn the gas off and stir till a glossy ganache is formed. Assemble! Very carefully unroll the cake and then use a spatula to spread on the whipped cream filling.
Reroll the cake. Once you've covered the entire surface of cake, roll it back up and put it in the fridge to set for about ½ - 1 hour.
Pour ganache. Remove chilled cake from refrigerator and drizzle on the topping. (or pour it on). Enjoy!