Melt the butter with the Merenda and the 100g of chocolate in a pot
We grind the cookies in the multi till they become a fine powder and we throw them in a bowl with the butter, the Merenda, and the couverture that we have melted. Mix well and spread the mixture in a 26 cm tart dish. Put the base in the fridge for at least half an hour.
For the filling, put the 200g couverture in a bowl. Heat the cream in a saucepan until it boils and pour over the chocolate. Mix well to make a glossy gauze.
Remove the tart from the fridge and pour over the ganache. Put back in the fridge to freeze for at least 2 hours.