Baklava can be made up to five days ahead. Store in an airtight container.
375g packet filo pastry, at room temperature
100g unsalted butter, melted
200g block dark chocolate, chopped
3⁄4 cup pure cream
Vanilla ice-cream, to serve
3 cups walnuts, toasted
1 1⁄2 cups blanched almonds, toasted
2 tblsps caster sugar
2 tsps ground cinnamon
1 cup caster sugar
1/3 cup honey
1⁄2 cup water
1 cinnamon stick
Lightly grease a 19cm x 30cm lamington pan. Line base and sides with baking paper, extending paper 3cm above pan edges.
2 To make filling, process both nuts in a food processor until finely chopped. Transfer to a large bowl. Stir in sugar and cinnamon.
3 To make syrup, place all ingredients in a medium saucepan over a low heat. Stir until sugar is dissolved. Bring to boil. Simmer for 5 minutes. Cool. Discard cinnamon stick.
4 Unroll filo onto a clean board with one long edge facing you. Trim both short ends, so filo length is 40cm. Cut in half crossways. Place one piece into prepared pan at one end. Brush with butter. Place next piece at the other end. Brush with butter. Repeat this layering once more.
5 Sprinkle over 1⁄2 cup filling. Repeat layering with remaining lo, butter and filling, finishing with filo. Brush top with butter. Freeze for 10 minutes.
6 Using a small, sharp knife, score through four layers of filo, making up 12 pieces.
7 Cook in a moderate oven (180C) for about 45 minutes, or until golden and crisp. Pour over syrup. Stand at room temperature for 2 hours before cutting.
8 To make chocolate sauce, place chocolate and cream in a heatproof bowl sitting over a saucepan of simmering water. Stir until smooth. Remove.
9 Lift baklava out of pan. Using a serrated knife, cut through score marks. Serve with warm sauce and ice-cream.