For the chocolate cookies, preheat the oven to 190 degrees and line two to three baking sheets with baking paper.
Beat the butter in a bowl until fluffy and gradually add the sugar. Stir in the vanilla flavoring and the egg, beating constantly.
Mix the flour and baking soda and fold into the batter together with the nuts and chocolate.
Spoon the dough into 2 tsp. heaps on the baking sheets. Leave a space of about 2 cm between the heaps.
Bake the chocolate cookies for about 10 to 12 minutes at 190 degrees and let them cool on a rack.