Whisk together the flour and baking soda in a medium bowl. Set aside. 

In another bowl, combine butter and both sugars and beat until light and fluffy. This is easiest with a standing or hand mixer.

While beating, add salt, vanilla, and eggs. Beat until mixed thoroughly. 

Add flour mixture to the butter mixture and mix until nearly combined.

Using a spoon, stir in oats and chocolate chips. 

Chill dough for at least one hour, preferably overnight. 

Preheat oven to 375°F.

Line 2 baking sheets with parchment paper.

Use an ice cream scooper to drop heaping balls of dough on the baking sheets. Space them about 2 inches apart since the cookies will spread while cooking.

Bake in the oven until the cookies are golden around the edges but soft in the center (about 8-10 minutes). Cookies will continue to cook after they are taken out of the oven. 

Remove cookies from the oven and allow to cool on baking sheet for 1-2 minutes before transfering to a wire rack and cooling completely.