Preheat the oven to 375 degrees F (190 degrees C).
In a large bowl, cream together the butter and brown sugar until smooth. Beat in the eggs one at a time, then stir in the vanilla. Combine the flour, baking soda and salt; stir into the creamed mixture. Mix in the oats, chocolate chips, vanilla chips, butterscotch chips and chopped pecans. Drop by tablespoonfuls onto ungreased cookie sheets. Cookies should be at least 2 inches apart.
Bake for 8 to 10 minutes in the preheated oven. Allow cookies to cool on baking sheet for 5 minutes before removing to a wire rack to cool completely.