Preheat oven to 180°C (350°F). Combine ground biscuit and melted butter until moist. Press into the base of the cake pan and bake for 12.5 minutes. Let cool.

Soak gelatin leaves in cold water. Heat milk with half the caster sugar until boiling. Whisk remaining sugar with egg yolks. Gradually combine with hot milk, return to heat and cook until thickened. Mix in bloomed gelatin and raspberry puree.

Whip heavy cream until stiff peaks form. Fold whipped cream into raspberry mixture. Pour over cooled cake base. Chill in refrigerator for at least 2 hours.

Heat milk with pistachio paste. Whisk egg yolks and sugar. Gradually combine with hot milk and cook until thickened. Add bloomed gelatin and cool.

Whip more heavy cream until fluffy. Fold into cooled pistachio mixture. Pour over raspberry bavarois. Refrigerate for at least 6 hours.

Remove cake from the fridge and pan. Slice and serve chilled, decorated with ground pistachio and fresh raspberries.