For the cookie base
350 ml double cream
375 grams of vanilla biscuit crumbs
1 teaspoon vanilla
For the Ganache
1 liter double cream, divided
800 grams chocolate
Preparation
In a large bowl, with an electric mixer on high, whip together the double cream and the vanilla until stiff peaks form. Tip in the biscuit crumbs in a few additions, beating on low, until a very thick batter forms. Lightly grease the bottom of a spring-form pan (23 cm; 9"), place the batter in the centre and gently press it out to cover the whole base. Set the pan aside, it does not have to be refrigerated.
For the Ganache, bring 500 ml of double cream almost to a boil, but do not let it boil, then pour it over the chocolate you grated or chopped up and placed in a large bowl. Let is sit for a few minutes, and then stir it with a spatula or a wooden spoon, until a thick and smooth Ganache forms. Let it sit at room temperature for about an hour. It needs to firm up and cool down. When the Ganache is ready, using clean, chilled beaters and a large bowl, whip the rest of the double cream with an electric mixer on high, until stiff peaks form. Gently fold it into the prepared Ganache. Pour that layer over the base in the pan, level it as much as possible and let it sit in the fridge overnight.
