Preheat oven to 350F degrees.
Combine flour, oats, baking soda, and salt in a medium bowl; stir with a whisk.
Place sugar and butter in a large bowl; beat with a mixer at medium speed until well blended (about 5 minutes).
Add vanilla and eggs; beat well.
Add flour mixture; beat just until combined. Stir in toffee bits.
Drop dough by tablespoonfuls 2 inches apart on 2 baking sheets coated with cooking spray.
Bake at 350 degrees for 9-11 minutes.
Cool on pans 1 minute. Do not overbake! The cookies don't look quite done when you pull them out, but they'll be perfect once they're cooled. Remove cookies from pans; cool completely on wire racks.