Method
1
Preheat the oven to 100°C.
2
Line a baking sheet with parchment paper.
3
Beat the egg whites with the lemon juice until foamy.
4
Add the meringue sugar gradually while beating.
5
Beat until the meringue forms stiff, glossy peaks.
6
Spoon the meringue into a piping bag fitted with a plain round tip.
7
Pipe 12 mushroom caps onto the lined sheet.
8
Pipe 12 tapered stems onto the lined sheet.
9
Bake the meringues for 90 minutes.
10
Turn off the oven and leave the meringues inside for 30 minutes.
11
Remove the meringues from the oven and let them cool completely.
12
Melt the 40 g of dark chocolate.
13
Make a small hole in the underside of each mushroom cap.
14
Dip the top of each stem in melted chocolate.
15
Press each stem into a hole in a cap to make a mushroom.
16
Leave the mushrooms until the chocolate sets.
17
Increase the oven temperature to 180°C.
18
Line a 25 x 38 cm baking pan with parchment paper.
19
Whisk the flour, cocoa powder, baking powder, and salt together.
20
Beat the egg yolks with half of the sponge sugar until pale and thick.
21
Stir 1/2 teaspoon of vanilla into the yolk mixture.
22
Beat the egg whites in a clean bowl until soft peaks form.
23
Add the remaining sponge sugar gradually while beating.
24
Beat until the egg whites form stiff peaks.
25
Fold the dry ingredients into the yolk mixture.
26
Fold the beaten egg whites into the batter in three additions.
27
Spread the batter evenly in the prepared pan.
28
Bake the sponge for 10 minutes.
29
Lay a clean kitchen towel on the counter.
30
Dust the towel lightly with powdered sugar.
31
Turn the warm sponge onto the towel.
32
Peel away the parchment paper.
33
Roll the sponge up in the towel from a short end.
34
Leave the rolled sponge to cool completely.
35
Heat the ganache cream until steaming.
36
Pour the hot cream over the chopped 200 g of dark chocolate.
37
Leave the mixture for 2 minutes.
38
Stir the chocolate and cream until smooth.
39
Stir the butter into the ganache until melted.
40
Chill the ganache until thick but spreadable.
41
Whip the filling cream with the filling powdered sugar and the remaining 1/2 teaspoon of vanilla until soft peaks form.
42
Unroll the cooled sponge carefully.
43
Spread the whipped cream over the sponge, leaving a 2 cm border along one long edge.
44
Roll the sponge up again without the towel.
45
Place the roll seam-side down on a serving platter.
46
Spread the ganache over the roll.
47
Drag a fork through the ganache to create bark-like lines.
48
Arrange the meringue mushrooms on and around the log.
49
Dust the log lightly with powdered sugar.
50
Arrange the cranberries and rosemary sprigs around the log.