Preheat the oven to 180 °C. Line the bottom of the springform with baking paper and grease the edge with butter.
Chop the chocolate for the cake roughly. Melt with the butter au bain-marie. Leave to cool slightly.
Beat the sugar with the eggs, salt and vanilla extract in a large bowl in about 6 minutes until light and airy. Sieve the flour above the creamed mixture. Gently fold the flour through the batter. Now gently fold the melted chocolate through the batter. Spoon the cake mixture into the cake springform. Bake the cake in the middle of the oven for about 40 minutes until cooked. Allow to cool completely.
Beat the cream and the sugar with the mixer to create a stiff mixture. Put in the fridge until needed.
Slice the cooled cake horizontally into three equal layers. Place a layer on a plate or serving dish and spread half of the whipped cream on top. Place a second layer on top of the first. Cover this layer with the rest of the cream and place the third layer on top.
Roughly chop 150 g chocolate for the topping. Melt with the butter au bain-marie. Leave to cool slightly. Pour the chocolate butter mixture over the cake and smooth with a palette knife. Leave the cake in the fridge for 1 hour so the topping can become firm.
Roughly chop the rest of the chocolate and melt au bain-marie. Brush the Oreo cookies with some melted chocolate and stick them onto the cake. Halve the strawberries. Decorate the cake with the strawberries and the rest of the Oreo cookies.