Preheat your oven to 350 degrees
In a large bowl, mix 12 tablespoons of room temperature butter with 3/4 cup of brown sugar and 1/2 cup of sugar until light and fluffy
Add 2 eggs and 2 teaspoons of vanilla extract and mix until creamy
Add 1 1/2 cups of all purpose flour, 1 teaspoon of baking soda, 1 teaspoon of ground cinnamon and 1/2 teaspoon of salt and mix until combined
Add 3 1/4 cups of oats in three parts (about 1 cup at a time) and mix until the oats are just combined
Add 1 cup of chocolate chips and mix only until they are evenly distributed
Place 2 tablespoons of dough onto non-stick or parchment lined baking sheets
Bake at 350 degrees for about 12 minutes
As soon as you see the edges begin to brown, remove them from the oven and allow them to cool on the baking sheet for 10 minutes
Transfer the cookies onto a cooling rack to cool fully
Store leftovers at room temperature in an air tight container