Preheat the oven to fan 140C/conventional 160C/gas 3. Butter and base line a loose-bottomed 20cm round cake tin. Put the butter, caster sugar, eggs, flour and ground almonds into a large bowl. Beat using an electric hand whisk until all the ingredients are well blended.
Spread half the cake mixture in the lined tin. Scatter over half of the amaretti biscuits then a third of the raspberries. Very lightly press into the cake mixture.
Dollop dessertspoonfuls of the remaining cake mixture over the amaretti and raspberries and spread evenly. Scatter the remaining amaretti and half the remaining raspberries over the top. Bake for 55-60 minutes, until a skewer inserted into the centre comes out clean.
Cool for 15 minutes in the tin. Run a knife round the edge and turn out. It will keep in a covered container in the fridge for up to 2 days.
To serve, remove from the fridge an hour before serving and lightly dust with icing sugar before bringing to the table. Serve with the remaining raspberries and a little single cream.