First, clean and chop the strawberries in rounds or small chunks. Place them in a bowl and add ¼ cup of sugar and lemon juice.
Cover the bowl with plastic wrap and let it rest in the fridge for at least 30 minutes.
Meanwhile, prepare the Mascarpone cream, starting by pasteurizing the eggs. In a saucepan, add the water and ½ cup of sugar and turn the heat to medium.
Use a candy thermometer and bring it to 250°F (121°C). A few minutes before it reaches the temperature, start whisking the egg yolks in a bowl.
When the sugar syrup reaches the right temperature, pour it slowly in a thin stream on the yolks, while keeping on whisking until they're light and foamy and until they're cooled down.
Add a couple of tablespoons of Mascarpone cheese to the whipped eggs and mix, then add the remaining Mascarpone and mix again until fully incorporated.
In another bowl, whip the cream until stiff peaks form, then add it to the eggs and mascarpone, folding it in carefully with a spatula.
Cover the bowl with plastic wrap and set it in the fridge until ready to use.
Take the strawberries out of the fridge, and blend ⅓ of them with their juices.
Dip both sides of the ladyfingers in the strawberry juice, then layer them on the bottom of a baking dish or glass trifle cups. You can cut the ladyfingers to the size you need to fill the whole surface.
Spread a layer of Mascarpone cream with a spoon on top of the ladyfingers, then sprinkle the chopped strawberries on top.
Make more layers until you fill the container, ending with a layer of Mascarpone cream.
Decorate the top with cocoa powder or with the remaining chopped strawberries.
Notes
Do I need a candy thermometer?If you want to pasteurize the eggs (see below), a thermometer can be really useful, otherwise, you may not pasteurize them correctly. A candy thermometer is preferable because you can clip it to the pot and have a constant measurement. But you can also use any other kitchen/meat thermometer. If you don't have any, you can eyeball it (not recommended) and turn off the heat when you start seeing white bubbles on the surface.