Step 1

Prep and measure all the ingredients.

Step 2

Make the chocolate swiss roll cake according to this recipe here. Follow that recipe until you have rolled up the warm cake, and it has cooled down to room temperature. You can let the cake cool down overnight.

Step 3

When the cake has cooled down, you can proceed with the rest of the recipe with the rolled up cake.

Step 4

Place the water in a small microwave safe bowl. Sprinkle the gelatin over the water and mix to saturate. Allow the gelatin to absorb all the water and bloom, for at least 5 minutes.

Step 5

After blooming, microwave the gelatin for 10 - 20 seconds, until it’s melted but NOT boiling.

Step 6

Add about ½ - 1 tbsp of cream to the gelatin mix while stirring to slightly lower the temperature of the gelatin mixture.

Step 7

Place the cream, cocoa powder, confectioner’s sugar, vanilla, and salt in a large mixer bowl. Whisk briefly to only combine the ingredients.

Step 8

With the whisk attachment, increase the mixer speed to high, and add the gelatin mixture directly into the cream while the mixer is running.

Step 9

Once the gelatin is added, reduce the mixer to a medium speed and whisk until you have soft peaks (thickened, but unable to hold a proper peak).

Step 10

Next, either lower the mixer speed a little more, or manually whisk the whipped cream until it reaches mid peaks (thick mixture, and can hold somewhat of a peak, but the mixture isn’t dry).

Step 11

The chocolate whipped filling is now ready - use immediately.

Step 12

Place the chocolate in a bowl. Also have a plate available that can cover the surface of the bowl.

Step 13

Heat the cream and salt in a saucepan over medium high heat, stirring occasionally.

Step 14

Heat the cream until it starts to simmer. Do NOT let it boil.

Step 15

When the cream is starting to simmer, pour it over the chocolate in the bowl. Cover the bowl for about 30 sec - 1 minute with the plate.

Step 16

Whisk the chocolate and cream mixture with a whisk until the chocolate has melted and is emulsified to form a smooth ganache.

Step 17

Let the ganache cool to about 70 - 72°F. Whisk regularly while the ganache is cooling, OR place a plastic wrap over the surface of the ganache (touching the surface) to prevent a skin from forming.

Step 18

When the ganache has thickened a little after it has cooled, it's ready to be whipped.

Step 19

Using a hand mixer or your stand mixer, whisk the ganache until it’s a shade lighter and looks a little fluffier (see photos in the post for reference). This will only take a few minutes depending on the speed of your mixer.

Step 20

The whipped ganache is now ready to be used as frosting.

Step 21

Carefully unroll the cooled swiss roll cake.

Step 22

Spread an even layer of the chocolate whipped cream filling, leaving a ¾ inch - 1 inch border at the short end with the diagonal cut.

Step 23

Now roll up the cake again, but make sure to loosen the parchment paper from the cake as you go. Make sure the cake is firmly rolled up, while maintaining its shape, and the filling isn't squeezed out much.

Step 24

Wrap the cake well with parchment paper and/or a cloth napkin so that the cake doesn't lose its shape. You can use the parchment paper to shape the cake if the roll seems loose. Let the cake chill in the fridge for at least 2 hours.

Step 25

While the cake is chilling in the fridge, you can prepare the whipped chocolate ganache (recipe above), or chocolate buttercream (recipe here).

Step 26

Remove the cake from the fridge and place it on a parchment paper lined tray to frost it. Trim the edges with a sharp, warm knife.

Step 27

OPTIONAL - If you’re making a branched yule log cake, cut the second swiss roll cake into two portions at an angle, and use the whipped chocolate ganache to attach one portion ('branch') to the main swiss roll cake. See pictures in the post for reference.

Step 28

Coat the entire cake with a layer of the whipped ganache. Work quickly to prevent the ganache from setting too much.

Step 29

Using either a spatula or a fork, create a tree bark-like texture on the cake. Optionally, you can coat/cover the ends of the cake with whipped ganache (as shown in the pictures in the post) to resemble a log.

Step 30

Cover the cake and refrigerate until you’re ready to serve.

Step 31

You can use a branched yule log cake for this as well.

Step 32

Apply a thin layer of the ganache on a section of the cake and attach the chocolate shards on top as shown in the pictures in the post. Repeat until the whole cake is covered.

Step 33

Cover the cake (being careful not to damage the chocolate shards), and refrigerate until you’re ready to serve.

Step 34

You will need a long piece of parchment paper to spread the chocolate, and a clean kitchen thermometer.

Step 35

Make sure all the bowls and spatulas are free of water, as any moisture will cause the chocolate to seize.

Step 36

Divide the chocolate into two portions - 75% (in weight) in one portion, and the rest of the 25% in another portion.

Step 37

Make sure both portions of chocolate are chopped into fairly small pieces, but especially make sure the 25% portion is cut even finer so it melts more easily.

Step 38

Bring some water to a simmer in a saucepan (about 2 inches of water).

Step 39

Place the 75% chocolate portion in a heat-proof bowl (glass or metal), and place it over the saucepan with simmering water. Stir to melt the chocolate, while making sure the mix doesn’t exceed 130°F (for dark chocolate) or 118°F (for milk chocolate).

Step 40

Remove the chocolate from the heat, and stir for a couple of minutes to cool it down.

Step 41

Add the chopped 25% portion and continue to stir and agitate the mix until the chocolate melts.

Step 42

The chocolate should cool down to 88 - 89°F (for dark chocolate) or 86 - 87°F (for milk chocolate).

Step 43

If the chocolate is still too warm after it has melted, add a little more chopped chocolate and stir to melt it in and cool down the mix further. Repeat until the chocolate has cooled down to the right temperature.

Step 44

The melted chocolate should have thickened by the time it's at the right temperature and is tempered, i.e. 88 - 89°F (for dark chocolate) or 86 - 87°F (for milk chocolate).

Step 45

Pour the tempered chocolate onto the parchment paper, and spread it as evenly as possible with an offset spatula, in a thin layer, on the parchment paper.

Step 46

Once the chocolate is spread, start rolling up the parchment paper before the chocolate starts to set.

Step 47

Allow the chocolate to set in the rolled up parchment paper (either a few hours at room temperature or a couple of hours in the fridge).

Step 48

When the chocolate is completely set, carefully unroll the rolled up parchment paper, while making sure the chocolate shards are breaking in long, large pieces.

Step 49

The chocolate shards are now ready. Store in an airtight container until needed.

Step 50

Preheat oven to 200°F and line a half sheet baking tray with parchment paper. Set aside.

Step 51

Place the egg whites in a clean, dry metal mixing bowl. Add the salt and cream of tartar.

Step 52

Whisk on medium high speed until the egg whites become frothy and start to form soft peaks.

Step 53

Add the sugar in a slow stream (or 1 spoon at a time) while whisking.

Step 54

Whisk until all the sugar is dissolved, and you have a thick, glossy meringue that is at stiff peaks.

Step 55

Place the meringue mixture in a piping bag, with a ½ inch round tip attached (or cut a similar sized hole).

Step 56

Pipe the meringue on the baking sheets, in two types of shapes, as described below.

Step 57

1 . Small, round mushroom caps, that are about 1 inch in diameter. Squeeze out a smooth blob of meringue until you get a rounded cap. Then stop squeezing, and in a circular motion, swirl the tip away from the meringue blob to create a smooth surface.

Step 58

2 . Small mushroom stumps with pointed tips. Slowly pipe the meringue onto the baking tray, but pull the tip up as you go to create a tall “stem” (about 1 inch tall). Stop piping as you pull the tip away to create a pointed end.

Step 59

Bake the piped meringue in the preheated oven for about 1 hour and 15 minutes, OR until the meringue pieces can be EASILY peeled off of the parchment paper. The length of time is very dependent on the oven, so check after about 60 - 70 minutes.

Step 60

Once the meringue is baked, turn off the oven, and let the meringue cool down in the oven with the oven door ajar.

Step 61

When they have cooled down completely, transfer them to an airtight container until needed.

Step 62

Using a toothpick, poke holes at the bottom of the mushroom caps.

Step 63

Spread a very thin layer of melted chocolate on the bottom of the mushroom caps.

Step 64

Dip the pointed end of a mushroom stem in melted chocolate, and attach it to the bottom of the mushroom cap, slightly pushing it against the hole you made with the toothpick. Place this on a tray and allow the chocolate to set.

Step 65

Once the chocolate is set, dust the meringue mushrooms with cocoa powder to make them look more realistic.

Step 66

Attach these JUST before you serve, as the meringue will get soft quickly when exposed.

Step 67

If you already have chocolate shards on your cake, then use melted chocolate to stick the mushrooms onto the cake.

Step 68

Or use whipped chocolate ganache to stick them onto the cake, if your cake is simply covered with ganache.

Step 69

Serve with a dusting of confectioner's sugar on top.