Place the flour, milk, eggs and a pinch of salt in a bowl and whisk to a smooth batter. Add a small splash of oil to a small nonstick pan over a medium heat then wipe with kitchen paper. When the pan’s hot, add a ladleful of batter, tilting the pan to spread, and cook for 2 to 3 minutes each side, until lightly golden. Set aside. Repeat until you’ve used all the batter, stacking the pancakes to one side.
Melt the smashed chocolate, butter and a pinch of salt in a heatproof bowl over a pan of gently simmering water (don’t let the bowl touch the water), stirring occasionally.
Meanwhile, smash the toasted nuts in a pestle and mortar, or in a clean tea towel with a rolling pin until fine. By now your chocolate should be melted, remove from the heat, stir through 200ml of cream and a handful of bashed nuts. Whisk the remaining cream with the vanilla and sugar until thick.
To build your cake, spread a blob of cream over a serving plate or board, pop a pancake on top and press gently. Spread some chocolate over the pancake and top with another pancake. Keep doing this, alternating between cream and chocolate, until you’ve used all the pancakes, remembering to keep some cream back for the top.
Smooth the sides with a spatula or palette knife to tidy up the edges, then pour the remaining cream on top. Let it drip down the sides and spread to cover the cake. Press the remaining nuts around the sides, then scrape over a few gratings of dark chocolate. Decorate the base with some lovely fresh raspberries, if you like, then serve.