Preheat the oven to 350°F. Line baking sheets with parchment paper.
In a large bowl, beat the softened butter, brown sugar, and granulated sugar until creamy.
Beat in the eggs one at a time, then stir in the vanilla extract.
In a separate bowl, whisk together the all-purpose flour, baking soda, ground cinnamon, and salt.
Gradually mix the dry ingredients into the wet ingredients until just combined.
Stir in the rolled oats until evenly mixed.
Drop dough by rounded tablespoonfuls onto the prepared baking sheets. Bake for 10 to 13 minutes or until golden brown.
Allow cookies to cool on the baking sheet for 1 minute, then transfer to wire racks to cool completely.