Preheat the oven to 300 degrees F (150 degrees C). Line cookie sheets with parchment paper.

In a medium bowl, cream together butter and brown sugar. Stir in egg and vanilla until smooth. Sift together flour, salt, and baking soda; stir into creamed mixture. Then stir in rolled oats. Finally, stir in pecans chopped candy bar pieces.

Drop dough by rounded tablespoons onto prepared cookie sheets, and flatten slightly. Bake for 10 to 18 minutes in the preheated oven. Cookies will have a dry appearance when finished baking.