All of the flour + sugar mix. Softened margarine, mix with sugar and flour until crumbs. Add the slaked soda, sour cream and knead the dough. Roll into ball and put in the cold for about half an hour. Preheat the oven. Remove dough, roll out in rectangular layer thickness of slightly less than 1 cm to Lubricate the surface with jam, roll up the roulade and put it in a preheated 200 degree oven for 20 minutes. When it becomes Golden, turn off, remove and cut into pieces of desired thickness. ALL READY!!! ENJOY YOUR TEA!