Combine dry ingredients.Set aside. Cream together oleo,and lard , add 3 whole eggs and 3 extra egg yolks.(reserve the 3 egg whites). Slowly add in flour mixture alternately with the sour cream.. Mix well to combine.Wrap in plastic wrap and refrigerate up to 3 days.
Mix together dates. water, lemon juice, butter, sugar and nuts.. Cook slowly until this mixture is thick and bubbly.Save in refrigerator until ready to use.
Roll dough as you would for sugar cookies, 1/4-inch thick. Cut in 2-inch squares. Fill each with square with a heaping teaspoon of filling. Put filling in the middle of square and fold 2 opposite corners together, pinching to close. Beat the 3 reserved egg whites and spread on top of each cookie, then sprinkle with sugar.
Bake on greased cookie sheet at 375^ for 12 to 15 minutes or until tops are lightly browned.