In a large mixing bowl, combine all crust ingredients except pecans. Beat at medium speed until crumbly. Press into bottom of 9 by 13 ungreased baking pan. Sprinkle pecans over unbaked crust.
For the filling: Combine butter and brown sugar in a saucepan. Cook over medium heat, stirring constantly, until mixture comes to a full boil, 4-5 minutes. Boil, stirring constantly, until candy thermometer reaches 242F 2-3 minutes.
Pour over pecans and crust. Bake at 350F for 18-20 minutes, or until caramel layer is bubbly. Remove from oven and immediately sprinkle with butterscotch and chocolate chips; let stand 5 minutes. Swirl chips as they melt leaving some whole for a marbled effect. Cool completely. Cut into bars.