Beat with a mixer margarine (at room temperature) and 120 g sugar to graying. Add 1 tbsp of water and 250 g of flour sifted so as to obtain a solid mixture. In another pot, whisk preground in large pieces walnuts, remaining sugar and cinnamon. From the solid mixture allocate 30 tbsp and shape them into small balls. Make a hole in the middle of them and put in 1/2 tsp walnut filling. Arrange biscuits in the pan, greased with the oil, and bake them for 20 minutes in an oven preheated to 170C degrees.