Soften the butter at room temperature or in the microwave. Combine the softened butter, sugar, brown sugar, eggs, and vanilla. Stir until the mixture is smooth and wet.
In a large bowl, combine the flour, baking soda, cinnamon, and salt.
Add the dry ingredients into the wet mixture in small portions at a time until they are completely combined.
Add the oats to the dough and mix thoroughly.
Roll the dough into golf ball sized balls and evenly space them out on a parchment paper lined cookie sheet.
Press each of the dough balls with a fork to form the cookies shape.
Bake in the oven at 375°F for 8-10 minutes, then remove and allow the cookies to rest on a cookie rack.