Recipe by: Maida Heater's Book of Great Cookies. pp. 58-9 Adjust a rack to the top position in the oven and preheat the oven to 400. Cut parchement to fit cookie sheets. Slit one long side of each date, stuff with one walnut half or a few pieces of walnut. Close the date around the nut and set aside. Sift together the flour, salt, baking powder and baking soda and set aside. Cream the butter, add the vanilla and the sugar and beat to mix well. Add the egg and beat thouroughly. On the lowest speed gradually add half the dry ingredients, then all of the sour cream, then the remaining dry ingredients. Scrape the bowl after each addition and beat only until combined. Transfer the dough to a shallow bowl for easier handling. Using two forks, drop each stuffed date into the the dough and roll it around until it is completely coated. There will be enough dough to cover each date, but don't overdo it or you won't have enough to go around. Using the forks, place the dough coated dates 2-3 inches apart on the prepared cookie sheets. Bake one sheet at a time for about 10 minutes until lightly browned. While baking, prepare the glaze. Melt the butter and mix it well with the remaining ingredients, using only enough milk to make the mixture the consistency of soft mayonnaise. Keep the glaze covered when you are not using it. Remove the cookies form the oven. With a pastry brush, immediatley brush the tops with a generous coating of the glaze. Transfer cookies to a rack to cool. Let them stand until the glaze is dry. ----