Combine dry ingredients (flour, cinnamon, salt, baking soda) and set aside.
In a large stand mixer fitted with the paddle attachment, or in a large bowl with handheld mixer, cream together butter and sugars on medium speed.
Once well mixed, add in vanilla and eggs. Mix until incorporated.
Then add in combined dry ingredients and mix until dough is formed.
Turning speed down to low, mix in oats until well combined.
Then slowly add in chocolate chips. I like to unlock the stand at this point (so it doesn't crush the chips) and mix in the chocolate chips with the mixer.
Once cookie dough is well incorporated, use a cookie scoop to scoop dough onto a parchment-lined cookie sheet. Leave a little space between each cookie, and after you scoop it, use the back of a small spatula to smoosh the cookie down and partially flatten in (see image below, I flatten about halfway). You're going to freeze the cookie dough in this flattened state, and then bake from this shape. Freeze dough for 30 minutes in the freezer.
Meanwhile, preheat your oven to 375°F.
Place cookie dough pieces on a parchment-lined baking sheet and bake for 7-9 minutes, until the tops are golden.
Top with a little sprinkle of flaked sea salt (or normal salt). Let rest for several minutes before eating to set. Enjoy! (These store well at room temperature in an airtight plastic container with lid.)