Heat oven to 375°F. In large bowl, beat margarine and sugars until creamy. Add eggs and vanilla; beat well. Add combined flour, baking soda and salt; mix well. Add oats and butterscotch morsels; mix well. Drop dough by level tablespoonfuls onto ungreased cookie sheets. Bake 7 to 8 minutes for a chewy cookie or 9 to 10 minutes for a crisp cookie. Cool 2 minutes on cookie sheets; remove to wire rack. Cool completely. Store tightly covered.