1 cup espresso coffee, or 8 teaspoons espresso powder dissolved in 1 cup boiling water
1 cup Frangelico hazelnut liqueur, plus more for filling (below)
¼ cup Frangelico hazelnut liqueur
1 pound (2 cups) mascarpone
30 savoiardi cookies (lady fingers), approx. 14 ounces
¾ cup chopped roasted hazelnuts
3 teaspoons unsweetened cocoa powder
1 x 8-inch square dish
For the Filling:
2 eggs, separated
1/3 cup superfine sugar

Combine the coffee and 1 cup Frangelico in a measuring jug, and allow to cool if the coffee is hot. 

Whisk the egg whites till frothy. In a separate bowl, beat the yolks and sugar with the G cup Frangelico for the filling. 

Add the mascarpone to the yolks and sugar mixture, beating it in well to mix. Gently fold in the foamy egg whites, and mix again.

Pour half of the coffee and Frangelico mixture into a wide shallow bowl and dunk enough savoiardi cookies for a layer, about 4 at a time, into the liquid, coating both sides. 

Line your tiramisu dish with a layer of soaked savoiardi cookies: they should be damp but not falling to pieces (though it wouldn’t matter if they did). Pour any leftover liquid from the dipping process over the layer you have made.

Put half the mascarpone mixture on top of the soaked cookies and spread to make an even layer.
Pour the remaining coffee and Frangelico mixture from the pitcher into the shallow bowl and make another, final layer of savoiardi, dipping as before and layering on top of the mascarpone in the dish.

Pour any leftover liquid over the savoiardi layer, and cover with the final layer of mascarpone. Cover the dish with plastic wrap and leave overnight, or for at least 6 hours, in the refrigerator. 

When you are ready to serve, take the tiramisu out of the refrigerator and remove the plastic wrap. Mix the chopped roasted hazelnuts with 2 teaspoons of the cocoa powder and sprinkle this over the top layer of mascarpone. Then dust with the final teaspoon of cocoa powder, pushing it through a strainer for lighter coverage, over the nut-rubbly tiramisu. 

Make ahead note:
The tiramisu can be made 1–2 days ahead and stored in the refrigerator. It will keep for up to 4 days in total and leftovers should be refrigerated immediately. 

Freeze note:
The tiramisu can be frozen for up to 3 months. Wrap the tiramisu (without hazelnut and cocoa topping) in double layer of plastic wrap and layer of aluminum foil. Thaw overnight in the refrigerator and top with nuts and cocoa, as directed in recipe

Credit: From Nigella Kitchen by Nigella Lawson. Copyright© 2010 Nigella Lawson. To be published October, 2010 by Hyperion. Available wherever books are sold. All Rights Reserved.