Beat the butter with an electric mixer until smooth and add the sugars. Cream together until well combined. Add the beaten egg until it is incorporated and then add the vanilla.
Mix the flour, soda and salt togther and gradually add to the sugar mixture. Then add the dates, pecans and oatmeail.
Divide dough into four portions and spread each portion into a 2 inch wide strip the length of the cookie sheet. I grease my cookie sheets. You can put two strips per sheet but leave room between them because they will spread out. Bake between 14-16 minutes at 350 degrees. Cool for 5-7 minutes then cut into bars (see photo) and serve. These keep well and are so tasty.