Heat oven to 350.
Combine flour, baking soda and salt in small bowl.
Beat butter, both sugars and vanilla in mixer bowl on medium-high speed until light and creamy, 2 minutes.
Beat in eggs 1 at a time, beating well after each addition, until mixture is fluffy.
At low speed, beat in dry ingredients just until blended.
Stir in chips and oats. Divide dough into thirds.
Place each piece in the center of its own large ungreased cookie sheet.
Press each piece with floured fingers to a 6-inch circle.
Bake 2 cookie sheets 17 to 19 minutes, switching pans halfway through, until cookies are browned and set.
Cool on cookie sheets 5 minutes.
With large spatula, transfer each cookie to wire racks; cool completely.
Repeat, baking remaining dough.
With a fork, drizzle half of melted chocolate over cookies; then divide and sprinkle baking bits over tops.
Drizzle cookies with remaining chocolate; let stand until chocolate sets.
(Can be made ahead. Wrap well and freeze up to 1 month. Thaw at room temperature 2 hours.)(Can be made ahead. Wrap well and freeze up to 1 month. Thaw at room temperature 2 hours.)
Cut each cookie into 8 wedges.
