Rinse the asparagus and break off the bottom. Peel the asparagus spears on the lower third and cut into 3 cm long pieces. Bring about half a liter of salted water with sugar to the boil and cook the asparagus pieces in it for eight to ten minutes over a low heat. Drain on a sieve.
Carefully stir in asparagus pieces, remaining butter, 40 g grated Parmesan and chopped parsley. Season the risotto with salt and pepper. Scatter the rest of the grated parmesan on top and serve the risotto immediately.