Chocolate Hazelnut Yule Log with Meringue Mushrooms

Start by making the meringue mushrooms (these can be prepared up to a week in advance). Preheat your oven to 120°C (100°C fan/gas ½) and line a baking tray with parchment paper. In a clean glass bowl, whisk the 2 egg whites using an electric mixer until they form stiff peaks. Gradually add the sugar, one tablespoon at a time, whisking constantly until the mixture is thick, glossy, and holds its shape.

Transfer the meringue to a piping bag with a large round nozzle. Pipe 12–15 mushroom caps by squeezing out small, squat circles onto the tray. Pipe an equal number of short vertical lines for the stems. Use a wet finger to gently dab down any sharp peaks. Lightly dust the caps with cocoa powder and bake for 1 hour. Turn off the oven and let them cool completely inside with the door closed.

For the sponge, increase the oven temperature to 180°C (160°C fan/gas 4). Line a 32 x 22cm Swiss roll tin with parchment paper. Whisk the 5 egg whites to stiff peaks, then gradually beat in half of the caster sugar until glossy. In a separate bowl, whisk the 5 egg yolks with the remaining caster sugar and vanilla until pale and fluffy. Stir in the chocolate hazelnut spread, then gently fold in the egg whites in three batches.

Sift the flour, 2 tbsp cocoa powder, and a pinch of salt over the egg mixture. Fold very gently until just combined, being careful not to deflate the air. Pour the batter into the prepared tin, spreading it to the corners. Bake for 12–15 minutes until the sponge is springy to the touch. Immediately cover the hot sponge with a fresh sheet of parchment and a clean, damp tea towel; let it cool completely in the tin.