Onto the sponge cake! Preheat your oven to 200 degrees Celsius and line a large baking tray with baking paper. You want to ensure you use a piece larger than your tray so you are able to remove the cake and flip it later. A cookie tray, approx 35x25cm in size actually works perfectly here.
In a large bowl place your eggs and using hand beaters beat until very light and fluffy.
Add in the sugar, a tablespoon or so at a time and continue to beat on high. Think of it like a pavlova except we're not quite looking for stiff peaks.
Continue to beat on high until the sugar is thoroughly dissolved and the eggs are thick and very fluffy. This will take a good few minutes!
Sift over the flour and cocoa powder and very very lightly fold together until just combined.
Pour into your prepared tray and gently spread out to the corners. Place into your hot oven for 8 minutes or until it puffs up and pulls away from the edges slightly.
Now you will be working with your sponge whilst it's still hot. So once cooked and removed from the oven, lay a second piece of baking paper out on your counter just larger than your tin and sprinkle with extra caster sugar. Using the hanging edges of baking paper, carefully remove your swiss roll and turn it upside down onto the sugar. Peel back the extra baking paper and discard.
Starting at one of the short ends, tuck the baking paper over the edge and gently start rolling your roll. Be sure to keep it quite loose, you want to leave enough room for cream and cherries and not put too much pressure on the roll so that it cracks. Honestly, don't stress if it does crack though, mine has and it's not the end of the world.
Place onto a wire rack to cool.