Step by step recipe:

1. 5 min.
   Warm 250 ml milk, 50 g caster sugar and 10 g Vanilla sugar.
2. 15 min.
   Put in a food processor bowl: 500 g flour, 50 g butter, 2 eggs, 20 g yeast and 1 pinch salt.
3. 2 hours
   Start kneading on slow speed, pouring in the milk and sugar mixture in a thin stream.
   
   Continue kneading for 5 minutes until the dough is smooth and evenly mixed.
   
   Cover the bowl and leave in a warm place to rise for 2 hours.
4. 5 min.
   After this rising time, tip the dough onto the worktop and roll out to 1 cm or ½ inch thick.
   
   Note: flour the worktop liberally as the dough is sticky.
5. 5 min.
   Cut the dough into circles about 7 cm or 2.5 inches in diameter.
6. 
   To fill the doughnuts you can use two methods.
   
   First method:
   
   Wet the tops of 2 circles of dough with a brush.
   
   Place a spoonful of jam on one of the circles.
7. 
   Place the second circle on top with the wet face downwards and press the edge down to seal it.
8. 
   Second method:
   
   Spread a circle of dough out with your fingers until it is about twice the size.
   
   Wet the top surface and place a spoonful of jam in the centre.
9. 30 min.
   Fold the edge in over the top and press to seal.
   
   Place the doughnut with the join underneath.
10. 1 hour
    Arrange all the doughnuts on a baking sheet, cover and leave to rise in a warm place for one hour.
11. 20 min.
    After they have risen, fry the doughnuts until they are golden brown on both sides.
12. 3 min.
    To finish, sprinkle a little icing sugar over the top.