Chocolate Fudge Ice-Cream Cake

Ingredients (serves 12)
14 oz hazelnuts
5 oz butter, at room temperature
1 cup pure icing sugar
3 eggs
8 oz dark chocolate
1/4 cup Kahlua or Tia Maria liqueur
3 quarts vanilla ice-cream

Directions:
Preheat oven to 400 F. Place nuts onto a baking tray. Roast for 10 minutes, or until skins split. Wrap nuts in a clean tea-towel. Stand for 10 minutes. Rub nuts in tea-towel to remove skins. Roughly chop.
Using an electric mixer, cream butter and sugar until pale. Add eggs, 1 at a time, beating well after each addition.
Melt chocolate in a bowl over a saucepan of simmering water, stirring with a metal spoon until smooth. Stir chocolate and liqueur into butter mixture.
Sprinkle half the nuts into a 3 inch deep, 10 inch (base) springform pan. Pour over half the chocolate mixture. Freeze for 30 minutes. Stand ice-cream at room temperature until slightly softened. Top with ice-cream, then remaining chocolate mixture. Cover. Freeze for 1 hour. Press remaining nuts into chocolate mixture. Cover. Freeze overnight. Slice. Serve immediately.