Step 1

Using coffee and the boiling water, prepare coffee in a plunger. Stand for 2 minutes, plunge coffee (or combine coffee and the water in a heatproof jug, stand for 2 minutes then strain through a fine sieve); pour into large jug, stir in liqueur.

Step 2

Beat egg yolks and sugar in small bowl with electric mixer until fluffy.

Step 3

Beat mascarpone, extra liqueur and extra sugar in large bowl until slightly thickened. Gently fold in egg yolk mixture.

Step 4

Pour half the coffee mixture into shallow bowl. Dip half the biscuits, a couple at a time, into coffee mixture until beginning to soften. Line base of 3-litre (12-cup) serving dish with biscuits; brush with any unused coffee mixture. Spread biscuits with half the mascarpone mixture and sprinkle with half the grated chocolate. Repeat with remaining biscuits, coffee mixture and mascarpone. Cover mixture, refrigerate overnight.

Step 5

Make hazelnut praline.

Step 6

Just before serving, sprinkle with remaining chocolate and chopped hazelnut praline.

Step 7

Preheat oven to moderate (180ºC/160ºC fan-forced).

Step 8

Place hazelnuts in shallow baking dish; bake about 8 minutes or until skins split. Rub nuts in tea towel to remove most of the skin; cool.

Step 9

Lightly grease oven tray.

Step 10

Combine sugar and the water in small saucepan; stir over low heat until sugar is dissolved. Brush side of pan with pastry brush dipped in water to remove sugar crystals. Bring to a boil. Boil, uncovered, without stirring, about 5 minutes or until mixture turns a toffee colour. Remove from heat, stir in nuts then quickly pour onto prepared tray.

Step 11

Stand until set.