PREHEAT oven to 375° F.
COMBINE flour, baking soda, salt and cinnamon in small bowl. Beat butter, granulated sugar, brown sugar, eggs and vanilla extract in large mixer bowl. Gradually beat in flour mixture. Stir in oats and morsels. Drop by rounded tablespoon onto ungreased baking sheets.
BAKE for 7 to 8 minutes for chewy cookies or 9 to 10 minutes for crisp cookies. Cool on baking sheets for 2 minutes; remove to wire racks to cool completely.
PAN COOKIE VARIATION:
Grease 15 x 10-inch jelly-roll pan. Prepare dough as above. Spread into prepared pan. Bake for 18 to 22 minutes or until light brown. Cool completely in pan on wire rack. Makes 4 dozen bars.