Peel the asparagus. Separate the tips and set aside for another dish.
Cut the asparagus stalks into small pieces.
Heat 30g butter in a saucepan and sauté the asparagus, stirring. Add the sugar, sprinkle over the flour and stir.
Deglaze with the stock and simmer for about 15 minutes, stirring occasionally.
Remove the bread crusts, dice and fry the cubes in a pan with the remaining butter until crisp.
Wash the parsley, shake dry and chop.
Add the cream to the soup and bring to the boil. Puree with a hand blender.
Pass the soup through a sieve, then season with salt and pepper. Serve in bowls and sprinkle with the croutons and chopped parsley.