Brown the butter. DW, you can do it! Place 8 Tbsp of the butter in a medium saucepan on medium heat. Look out for these indicators: The butter will take a few minutes to fully melt. Once it is fully liquified, you must stir it constantly with a whisk or by swirling the pan, while waiting for it to boil/release steam. It’s boiling when you see some vigorous bubbling and foaminess. Keep swirling and stirring! The big boisterous bubbles mean you’re about one step away from brown butter. These big bubbles are eventually going to turn into a cohesive, foamy layer, in which all the bubbles are miniscule and, well, foamy. Keep stirring! Turn the heat to low. When you start to see golden solids at the bottom of the pot, your butter is about done and browned. Set aside in a large mixing bowl to cool.
While the brown butter cools, use the same saucepan and add the remaining 4 Tbsp butter, oats, and sesame seeds. Fry everything on medium heat, stirring constantly. for about 5-6 minutes—until the sesame seeds turn golden brown and the everything is fragrant.
In a large mixing bowl, whisk the sesame oil, sugars, and browned butter together until fully combined and a bit lighter in color. Once it’s all together, add your eggs and vanilla and mix again till fully combined. In a medium bowl, whisk the flour, cornstarch, baking soda, and salt. Add the dry ingredients, fried oat mix, and chocolate chips to the wet ingredients and fold everything together with a rubber spatula.
Portion the cookies into balls with an ice cream scoop or just estimate with a tablespoon. Place the cookie dough balls on a lined tray and place in the fridge to rest for an hour.
Preheat the oven to 350 degrees F. After they’re done resting, arrange the balls at least 1.5 inches apart on a lined cookie sheet. Bake in the middle rack of your oven for 12-13 minutes or until the edges are golden brown. Remove from the oven and let cool for at least 20 minutes!
Eat and die happily.