Chocolate-filled Sponge Roll Bites

Preheat your oven to 180°C (160°C fan-assisted). Line a large baking tray (approx. 30x40 cm) with parchment paper. Separate the eggs. Whisk the egg whites with a pinch of salt until stiff peaks form, then gradually add half of the sugar and continue whisking until you get a shiny, stable meringue. Gently fold in the egg yolks one by one. In another bowl, sift together the flour, cocoa powder, and baking powder. Carefully fold the dry mixture into the egg mixture in several batches. Spread evenly on the baking tray and bake for 10-12 minutes, until golden brown and springy to the touch.

As soon as you remove it from the oven, invert the hot sponge cake onto a lightly damp, sugar-dusted kitchen towel. Carefully peel off the parchment paper, then use the kitchen towel to tightly roll up the sponge cake. Let it cool completely in its rolled state.

Break the dark chocolate into small pieces and place them in a heatproof bowl. Bring the heavy cream to a boil in a small saucepan, then pour it over the chocolate. Let it sit for 1-2 minutes, then stir until smooth. Add the butter and stir until it's completely melted and you have a shiny, homogeneous cream. Set aside to cool until it reaches room temperature and thickens slightly (about 30-45 minutes).

Carefully unroll the cooled sponge cake. Spread the thickened chocolate ganache evenly over it, leaving a small border around the edges. Roll the sponge cake up tightly again. Wrap it in cling film and refrigerate for at least 1-2 hours, or even overnight, to allow the ganache to set completely and the roll to become firm.

Remove the roll from the refrigerator and slice it into bites of about 2-3 cm thickness with a sharp knife. Dust with powdered sugar and serve immediately. Enjoy!