Preheat oven to 350 degrees F.
In the bowl of a stand mixer fitted with a paddle attachment, beat the cool butter until creamy. Add salt and both sugars and continue beating until smooth -- don't try to beat until fluffy or light, just smooth. Add the egg and beat just until mixed, then beat in the vanilla.
Mix together the flour and the baking soda. Stir flour mixture into the egg mixture until blended. Stir in the oats and the chocolate chips.
Scoop up about 32 heaping tablespoons of batter and shape into balls. Press tops of balls down slightly to make discs. Chill the balls until ready to use or bake immediately.
To bake, arrange dough pieces about 2 ½ inches apart on parchment lined baking sheets. Bake for 12 to 15 minutes or until cookies appear set. Let cool for about five minutes on baking sheets, then transfer to a wire rack and let cool completely.