Preheat the oven to 200°. Line two baking trays with baking paper.
Beat the butter with the two sugars, salt and vanilla until light and creamy.
Stir the eggs and then the flour mixed with baking powder into the dough.
Chop the nuts, stir together with the chocolate and the dough.
Place the dough on a baking tray, spoon by spoon, with a very large gap between them. Bake the cookies for 10-12 minutes (fan oven at 180°), then let them cool on a cake rack.