375g wheatmeal biscuits
90g chopped walnuts
125g unsalted butter
3/4 cup castor sugar
1/3 cup Dutch cocoa
2 eggs, lightly beaten
125g bittersweet chocolate, chopped
1 tbsp dark rum
60g unsalted butter
Lightly butter a 20cm square tin. Break biscuits into small pieces and put into a large mixing bowl with walnuts.
Melt butter with sugar, stirring until sugar has dissolved. Mix in cocoa, then stir over heat until smooth. Allow to cool.
Stir eggs into butter mixture, then pour this over biscuit and walnuts. Mix very well. Press into prepared tin in a 2cm deep layer. Chill while you make the icing.
Put chocolate, rum, and butter into a bowl over hot water and stir until melted. Pour onto hedgehog and tilt tin to achieve a smooth, even layer. Refrigerate briefly to set icing before cutting into 4cm squares.