Anette's Nøddekage (from Mor)

100 g (3 1/3 oz) butter
300 g (10 1/2 oz) sugar
1 1/2 dl (10 tbsp) whipping cream
2 eggs
125 - 150 g (5 oz) flour
1 tsp baking powder
100 g (3 1/3 oz) coarsely ground/chopped hazelnuts