Preheat oven to 350°F. Spray 9 x 13 in. pan with vegetable pan spray.

In medium bowl, stir together flour, 1-1/2 cups oats, baking soda, cinnamon, salt, and nutmeg.

In large bowl, beat butter and brown sugar with electric mixer until light and fluffy. Add eggs, one at a time, beating well after each addition. Add vanilla. Add flour mixture and mix until just combined. Stir in 3/4 cups butterscotch chips and pecans, if using. Press mixture evenly into prepared pan. Sprinkle remaining oats and butterscotch chips over top.

Bake 30-35 minutes or until toothpick inserted in center comes out almost clean. Remove to cooling grid; cool completely.