Preheat the oven to 150°C/300°F/Gas mark 2
Cream togetrher the icing sugar/confectioner's sugar and butter. Add the vanilla and sour cream and blend well. Stir in the flour, poppy seeds and salt. Mix thoroughly.
Drop by teaspoonful about 1 inch apart onto an ungreased cookie sheet. With your thumb, make an imprint in the centre of each cookie. Fill with about 1/2 a teaspoon preserves. Bake for 20 min. or until the edges are starting to turn light golden brown. Remove from the cookie sheets and cool on a rack.
