Make base by melting butter - add to crushed Amaretti biscuits. Mix, then press into base of a buttered 20cm. loose bottom cake tin. Place three-quarters of the Mascarpone cheese in a bowl. Beat well to soften, then add coffee & brandy. Melt chocolate in basin over hot water then add to the Mascarpone mix. Whip cream until it just holds its shape and fold into the above mix. Pour over base, cover and chill in fridge till firm. Whip remaining Mascarpone and icing sugar till smooth. For added luxury, mix 150ml. unwhipped double cream into the Mascarpone and sugar. Remove torte from tin and spread whipped mixture evenly over the top. Sprinkle with cocoa powder.