Melt or brown the 1/2 cup butter. To melt- microwave in 30 second increments in a microwavable safe bowl.
To brown the butter, start by cutting the cold butter into small pieces. Add the butter to a sauce pan and melt over low heat. When the butter starts to foam grab a whisk and start stirring. This will help your butter from melting too fast and possibly burning the milk solids. Continue stirring and watch as the white milk solids separate and sink to the bottom of the pan. When they turn a golden brown color and it smells super nutty, take the pan off the heat. Cool. If the milk solids turn black, strain them and use the rest of the melted butter for the recipe.
Add the cooled butter to a large size mixing bowl along with the brown sugar, eggs, and vanilla extract. Whisk until a paste forms.
Add the oats, flour, baking soda, cinnamon, salt, and chocolate leaving behind one handful of the chocolate chips. Mix the batter with a spatula just until it comes together. It will be thick but should be uniform.
Preheat the oven now to 350°F. Scoop out the dough using a cookie scoop, ice cream scoop, or tablespoon and place on a cookie sheet. Press left over chocolate chips onto each dough ball. Don't be afraid to press them in! Freeze for 20 minutes.
Line a cookie sheet or sheet tray with parchment paper and bake 5-6 cookies per sheet leaving at least an inch border in between each cookie. These dont spread too much but they spead a little!
Bake for 18-20 minutes. Until crispy on the edges.