Speculoos, vanilla & chocolate log

Vanilla, chocolate, and speculoos—the program for log n°4 this year! Unlike the other logs, the insert of this one doesn’t need to be completely frozen for assembly since it's a rolled biscuit, so in terms of organization, you can do it all in the same day if it suits you (but of course, you can also prepare it over several days and freeze the different parts gradually). Finally, if some want to enhance the speculoos taste, you can add a bit of cinnamon powder in the vanilla mousse 😊
 
Equipment:
Silikomart log mold (I used the mold without the patterned mat)
Thermometer
Whisk
Perforated tray
Piping bags

Ingredients:
I used Koro's speculoos paste Koro: code ILETAITUNGATEAU for a 5% discount on the entire site (non-affiliated).
I used Norohy vanilla & Valrhona's Jivara chocolate Valrhona: code ILETAITUNGATEAU for a 20% discount on the entire site (affiliated).

Preparation time: 1h40 + 25 minutes of baking + freezing/defrosting
For a 25cm log:

Milk chocolate speculoos ganache:
 
96g of heavy cream
65g of speculoos paste
65g of milk chocolate
15g of neutral honey, such as acacia
20g of butter
 
Heat the cream with the honey.
In parallel, melt the chocolate. Add the speculoos paste.
Then, pour the hot cream in three parts over the chocolate-speculoos mixture, mixing well after each addition. When the ganache is smooth and shiny, add the butter in small pieces, and stir again until completely incorporated.
 

 
Cover the ganache and let it cool/crystallize completely.
 
Choux pastry biscuit:
 
50g of whole milk
50g of T55 flour
35g of butter
35g of whole eggs
70g of egg whites
60g of egg yolks
45g of sugar
 
Bring the milk and butter to a boil.
 

 
Off the heat, add the flour all at once, mixing well with a wooden spoon, then put the saucepan back on medium heat to dry out the dough (which means stirring it over the heat for a few minutes until a film forms at the bottom of the pan).
 

 
Transfer the dough into the bowl of a mixer fitted with the paddle attachment and run it until the steam has stopped escaping from the dough.
If you don’t have a mixer, you can stir with a spatula, it will simply take more time. Then gradually add the whole eggs and egg yolks until you have a homogeneous dough.
 

 
Beat the egg whites until stiff, then tighten them with the sugar until it is completely dissolved.
 

 
Add a spoonful of meringue to the choux pastry, mixing vigorously, then gently fold in the rest using a spatula.
 

 
Spread the dough on a tray lined with a baking mat or parchment paper, forming a rectangle about 30cm by 25cm.
 

 
Bake the biscuit in the preheated oven at 180°C for 15 to 20 minutes (watch the end of the baking, the biscuit must remain soft to be rolled). Let cool.
 

 
Once the biscuit is cooled and the ganache has a creamy texture, spread it in a thin layer on the biscuit.
 

 
Roll the biscuit, then trim the sides to have a 25cm long roll.
 

 
Place it in the freezer while preparing the other elements.
 
Reconstituted speculoos base:

125g of speculoos
45g of butter
 
Grind the speculoos into powder.
 

 
Add the melted butter and mix well, then spread the mixture on parchment paper to the size of your log mold (so 24 x 7cm here).
 

 
Open the paper, then bake in a preheated oven at 180° for 10 minutes. Let cool completely before moving the biscuit.
 

 
Vanilla mousse:

2.7g of gelatin
70g of whole milk
15g of mascarpone
1 vanilla pod
15g of granulated sugar (1)
25g of egg yolks
10g of granulated sugar (2)
300g of heavy cream (30 or 35% fat content)
 
Start by preparing the crème anglaise: put the gelatin in a bowl of very cold water.
Bring the milk, mascarpone, vanilla seeds, and sugar (1) to a boil.
 

 
Beat the egg yolks with the sugar (2). Pour half of the boiling milk over, whisking well, then pour everything back into the saucepan.
 

 
Cook over low heat until it reaches 85°C. Add the rehydrated and drained gelatin, then let the cream cool.
 

 
Whip the very cold cream until you get a not too firm whipped cream.
When the crème anglaise is about 30°C, add a small part of the whipped cream and incorporate it by mixing vigorously. Then gently add the rest of the whipped cream, making sure not to deflate the mixture.
 

 
Proceed immediately to assembly.
 
Assembly:

Pour half of the mousse into the yule log mold.
 

 
Add the rolled biscuit as an insert.
 

 
Cover with mousse, then finish with the speculoos biscuit.
 

 
Place in the freezer until fully set.
 
Milk chocolate & speculoos whipped ganache, decoration:

175g of 40% milk chocolate
380g of heavy cream
50g of speculoos paste 
1 speculoos biscuit 
 
Melt the milk chocolate slowly in a double boiler or microwave. Add the speculoos paste. Heat half of the cream, then pour it in three times over the melted chocolate while mixing well, to create an emulsion. 
 

 
Add the second half of cold cream, mix well, then cover with plastic wrap touching the surface, and refrigerate for at least 6 hours, preferably overnight. 
 

 
Unmold the log, place it on your serving dish, and let it defrost in the refrigerator for at least 3 hours. Then, whip the ganache until it has a whipped cream texture. 
 

 
Pipe it onto the log, decorate with crumbled speculoos, and finally, enjoy!