1 Break the white chocolate into a heatproof bowl and melt over a pan of simmering water. Remove from the heat and allow to cool. Roughly chop the milk chocolate. 2 Lightly whisk the cream until it forms soft peaks. Mix the mascarpone and icing sugar until smooth and softened. 3 Beat in the melted white chocolate and the chopped milk chocolate. Gently fold in the cream. Pour the liqueur and coffee into a shallow bowl and dip half the sponge fingers into the liquid. Use to line a glass serving bowl. 4 Cover the sponge fingers with half the mascarpone mixture. Top with the remaining sponge fingers followed by the remaining mascarpone mixture. 5 Chill the tirasmisu for at least an hour. Dust with cocoa to serve. Variation: 1 For a Tiramisu Tart: Make the base using crushed gingernuts and butter, and spread into 20cm flan tin. Pour in the filling and place in the fridge to set. Dust with cocoa to serve. Per serving: 326 Calories (kcal); 18g Total Fat; (46% calories from fat); 3g Protein; 42g Carbohydrate; 6mg Cholesterol; 26mg Sodium Food Exchanges: 0 Grain(Starch); 0 Lean Meat; 0 Vegetable; 0 Fruit; 3 1/2 Fat; 2 1/2 Other Carbohydrates Converted by MM_Buster v2.0n.