Preheat oven to 400° F and spray two baking sheets with cooking spray (or line with parchment paper).
Slice the cold butter into 1-inch cubes and place in the standing mixer, along with the brown and cane sugars. Gradually increase speed and mix on high for 3-4 minutes until creamy. Scrape down the sides of the bowl halfway through.
1 cup cold butter, sliced into ¼ in cubes, 1 ¼ cup light brown sugar, packed, ½ cup cane sugar
In a separate bowl, whisk together the flour, sea salt, cornstarch, and baking soda.
2 ½ cup all purpose flour, 1 teaspoon fine sea salt, 2 teaspoon cornstarch, 1 teaspoon baking soda
After creaming the butter and sugar, add vanilla and eggs and mix on medium speed until well combined. Scrape down the sides of the bowl halfway through.
2 large eggs, 1 tablespoon vanilla extract
Add mixed dry ingredients to the standing mixer and mix on the lowest setting until just combined. Add chocolate chips while flour is still mixing in--this minimizes the risk of overworking the cookie dough.
2 ½ cup semisweet chocolate chips (I prefer Ghirardelli)**
Roll the dough into 12 balls and place 6 on each baking sheet. If you'd like, press extra chocolate chips into the top of each cookie. I typically bake for 9 minutes, but it could range between 8-10 minutes depending on your oven. Only bake one baking sheet at a time. Rotate pan 180° halfway through baking. Keep a close eye on them so they don't overbake. The cookies should start to brown on top, and a little at the bottom. Don't worry about them being super soft, they'll continue to set after baking.
Leave the cookies on the pan for at least 15 minutes so that they continue to cook through and solidify. Enjoy!