Line a 12-section bun tray with paper cake cases. Put the amaretti biscuits in a polythene bag and crush with a rolling pin.
Tip the crushed biscuits into a bowl and add the muscovado sugar, butter, eggs, flour and baking powder. Beat with a hand-held electric whisk for about a minute until pale and creamy. Divide the cake mixture between the paper cases.
Bake in a preheated oven, 180°C (350°F), Gas Mark 4, for 20 minutes or until risen and just firm to the touch. Transfer to a wire rack to cool.
Beat the cream cheese with a wooden spoon in a bowl to soften, then beat in the icing sugar. Spread over the tops of the cakes with a small palette knife. Arrange a layer of raspberries on top and dust with icing sugar.