Heat oven to 375°F. Lightly grease 13 x 9-inch baking pan. In large bowl, combine oats and flour; mix well. Remove 2/3 cup and add salt and red pepper; set aside for filling. To remaining oat-flour mixture, add butter, granulated sugar and vanilla; blend with electric mixer on low to medium speed until crumbly. Reserve 1 cup for topping. Press remaining mixture evenly onto bottom of prepared pan. Bake 15 minutes; remove pan from oven. In separate bowl, combine sweet potato, eggs, brown sugar, bourbon and reserved 2/3 cup oat-flour mixture; mix well. Spread filling over warm crust. Add nuts to reserved topping mixture; mix well. Sprinkle evenly over sweet potato filling. Bake 30 to 35 minutes or until topping is light golden brown. Cool in pan on wire rack; cut into bars. Serve at room temperature. Store in refrigerator tightly covered.