Steps

• Preparation of the Soak
  In a small saucepan, combine the water and the sugar.

  Bring to a boil until the sugar is completely dissolved. Turn off the heat, add the limoncello and the lemon juice. Let cool completely before using.

  

• This step is fundamental to consume the dessert safely.
  Start whipping the yolks with 1/4 cup of sugar in a stand mixer or with an electric mixer until they become pale.

  

• At the same time, put 1/2 cup of sugar with 2 3/4 tbsp of water in a small saucepan. Cook over medium heat while monitoring with a kitchen thermometer: the syrup must reach 250°F.
  When the syrup reaches the temperature, pour it slowly in a thin stream onto the yolks while continuing to beat at medium speed.
  Keep whipping until the mixture has completely cooled. You will obtain a foamy, pale and safe base.

  

• In a large bowl, briefly beat the mascarpone with a spoon to soften it, adding the lemon juice.
  Gently fold the pasteurized yolk mixture into the mascarpone, mixing from the bottom up.

  

• Separately, whip the very cold cream to stiff peaks and fold it into the rest of the cream with slow movements so as not to deflate it.

  

• “layering lemon tiramisu with ladyfingers”

  Take the mold — as you can see I made a very tall tiramisu so I used an acetate cake collar.

  If you cannot find it you can use a very large baking dish.

• Spread a thin layer of cream on the bottom.
  Quickly dip the ladyfingers into the limoncello soak (not too long to avoid disintegration) and create the first layer.

  

• Cover with mascarpone cream, leveling well.

  

• Repeat the operation with a second layer of ladyfingers

  

• and with the cream

• until you have used all the ingredients.

  

• Put the remaining mascarpone cream into a piping bag fitted with a star tip and decorate the surface with grated lemon zest or strips.
  

  Let the cake rest for at least 6 hours (better if overnight) to allow the flavors to meld.

  

• Preparation of the Soak (Thermomix)
  Place the water and sugar in the bowl: 5 min / 194°F / speed 1.
  Add the lemon juice and the limoncello: 20 sec / speed 3.
  Transfer to a bowl and let cool completely. Wash and dry the bowl well.

  

• 2. Pasteurization of the Yolks (Thermomix)
  This step replaces the 250°F syrup method by using constant cooking.
  Attach the butterfly. Put the yolks and 3/4 cup of sugar (all together) into the bowl: 10 min / 176°F / speed 3.

  

• Once finished, continue to whip to cool the mixture: 5 min / speed 3 (without temperature).
  Transfer the mixture (which will be voluminous and very pale) to a large bowl and let it rest a few minutes.

  

• The Mascarpone Cream (Thermomix)
  Wash the bowl thoroughly with very cold water and dry it well (or use an already cold bowl).

  

• Attach the butterfly and pour in the very cold cream: speed 3, monitoring through the hole until it is whipped (usually between 2 and 4 minutes, depending on temperature). Set aside.

  

• In the clean bowl (without the butterfly), put the mascarpone and the lemon juice: 20 sec / speed 3 to soften it.
  Combine the mascarpone with the pasteurized yolks, mixing gently by hand with a spatula.
  Finally, fold in the whipped cream with movements from the bottom up so as not to deflate the mixture.

  

• Assembly
  Proceed as in the classic version:
  Layer of ladyfingers soaked in limoncello.
  Generous layer of cream.
  Second layer of ladyfingers and finishing cream.
  Decorate with lemon zest.