In a bowl, whip heavy whipping cream with a hand held mixer for 3 minutes. Set aside.
Melt the dark chocolate in a microwave together with the butter.
Let your chocolate sit at room temperature.
Separate egg whites from yolks; then, beat the egg whites until stiff with an electric hand mixer. Add in a pinch of salt while beating. When you hit soft peaks form, add in the sugar little by little.
Now that the buttery chocolate is at room temperature, add the egg yolks one by one, stirring each yolk until each one is integrated.
In batches, add the meringue to the chocolate mixture and mix with slow folding movements so it doesn’t deflate. Then, add in the whipped cream and combine with the same folding technique until well integrated.
Line 8 inch cake pan with parchment paper.
Dip the Maria cookies in milk and place them on the base of the mold.
Fill the cake pan with the mixture and cookies, making sure you don´t leave gaps. The order is the following: cookies – mixture – cookies – mixture.
Once you’ve assembled the cake, put it in the fridge overnight so that it’s ready for the next day. Et voilà … You have for dessert a delicious chocolate mousse cake!