Danish apple doughnuts (æbleskiver)

Method

1. Dissolve the yeast in the milk in a large bowl, then whisk in the egg yolks. In a separate mixing bowl, combine the flour, salt, cardamom, sugar and vanilla seeds, mixing well.
2. Add the dry ingredients to the milk mixture and beat to make a smooth batter, like a thick pancake batter.
3. In a separate clean bowl, whisk the egg whites until stiff, then fold into the batter. Leave to rest for 40 minutes.
4. Heat the æbleskiver pan over a medium heat. Put a tiny knob of butter in each indentation and, when it has melted, pour in some of the batter. Put a piece of apple in the middle of each, then cook for 3-5 minutes or until golden underneath. Turn the doughnuts over using a skewer, continue frying for 4-5 minutes until golden, then remove from the pan. Repeat with the remaining batter.
5. Dust with icing sugar and serve immediately with raspberry jam.