Preheat the oven to 160°C. Melt the butter in a 28cm ovenproof frying pan over a low heat, while you blitz the biscuits until fine in a food processor. Turn the heat off, tip the biscuit crumbs into the pan and mix well, then spread and pat out in an even layer, going slightly up the sides. Bake for 5 minutes, then remove. Crack the eggs into the processor (there’s no need to clean it), with the vanilla and most of the icing sugar and blitz for 2 minutes, until pale. Blitz in the cream cheese and lemon juice, then pour evenly over the biscuit base. Mash half the raspberries and the remaining icing sugar with a fork, swirl through the top, then bake for 15 minutes.
Pull out the pan and scatter over the rest of the raspberries, dust with a little extra icing sugar, then pop back in for another 10 minutes. At this point, switch from the oven to the grill on full whack, until the top is beautifully golden and just starting to catch. Remove and leave to cool, then chill in the fridge for 2 hours before serving. The texture won’t be completely smooth but boy will it be delicious.