Preheat the oven to 160ºC conventional or 140ºC fan forced. Grease a 6 x 3/4 cup Texas muffin pan.
Beat butter and chocolate icing sugar in a bowl with an electric mixer until light and creamy. Add ground hazelnuts, cocoa and chocolate and mix until just combined.
Add eggs gradually, beating well between additions. Stir in polenta and milk.
Spoon mixture into prepared pans. Bake for 30 minutes or until cooked when tested with a skewer.
Chocolate Sauce: : Combine chocolate and cream in a heatproof bowl and stir over a pan of simmering water until chocolate is melted. Place puddings on serving plates and drizzle with warm chocolate sauce.