Sift together flour, baking powder and salt. Cream butter, sugar, sour cream, lemon peel and beat well. Add eggs, one at a time, and then milk. Gradually, add the sifted dry ingredients, scraping the bowl as necesary with a rubber spatula and beating only until thoroughly mixed. Divide dough into 2 halves. Wrap each atch with foil or plastic wrap and chill in refirgerator for 3 hours or longer. Do not place dough in freezer. Preheat oven to 200ºC Place one batch of dough on lightly floured pastry cloth. Turn dough to flour all sides and roll out to desired thickness. For very large cookies, 1 cm. Cut the cookeis as you wish. Transfer cooies to ungreased cookie sheets. If cookies are large and thick, place at least 5 cm apart. Sprinkle the tops of the cookies generously with granulated sugar. Bake until the cookies are lightly browned. Large, thick cookies will need to bake for 10-12 minutes. Transfer cookies to racks for cooling. ----