- Combine the eggs and sugar together, then beat them until you get a light-colored fluffy mixture. Pour in the kefir and the oil, mix on low speed.
- Add the flour together with the baking powder and starch. Mix with a spatula until combined.
- Preheat the oven to 180C (356F), then line your baking tray with baking paper and grease it with some vegetable oil. Pour the sponge batter onto the tray, even it out with a spatula and bake for about 15 minutes.
- While the sponge is baking, line your work surface with some more baking paper, then sprinkle it with sugar heavily. Once the cake is ready, remove it from the oven.
- Put the sponge upside down so that its top part would touch the sugar, remove the baking paper sheet from its bottom, then cover it with a new one. Place another baking tray onto the sponge and put some weight on top of it for the cake to flatten.
- Leave the sponge to sit like this for 30 min., while making the syrup and the filling in the meantime.
Brew 2 tsp of coffee with 150 ml (5.10 fl oz) of boiling water, then add 1 tbsp of Amaretto and leave the syrup to cool.
Whip the cream until stiff. In a separate bowl, combine mascarpone and castor sugar together, mix carefully until incorporated. Start gradually pouring in the whipped cream, while continuing to beat the mixture on low speed. And your filling is ready.
- Remove the weight and the sheet of baking paper from the sponge and trim the edges to make it more even.
- Soak the sponge with the coffee syrup, then spread the filling over it. Grate the chocolate and sprinkle it on top of the cake followed by the cocoa powder.
- Start gradually rolling the sponge cake. Once the roll has been formed, wrap it in the sheet of baking paper that it’s been lying upon, then transfer it to the freezer for half an hour.
- Once it has chilled, remove the tiramisu roll from the fridge, then frost it with the rest of the filling. You can also use it to make some cream swirls on top of the roll if you want. Dust the roll with some cocoa powder. And enjoy!