Preheat oven to 350°F and line two to three baking sheets with parchment paper.
Cream butter and brown sugar on medium speed with a mixer until combined and fluffy. Add vanilla and eggs; mix until just combined.
Whisk together flour, baking powder, cornstarch, and salt. Add half of flour mixture to the butter mixture. Mix on low speed until just combined, and then medium speed until completely combined. Repeat with second half of flour mixture. Fold in chocolate chips.
Using a cookie scoop (I used a 2 tablespoon scoop), scoop dough onto the prepared baking sheet, arranging 2-inches apart. Press about 5 to 6 additional chocolate chips onto the top of each ball of dough.
Bake cookies for 8 to 10 minutes, or until crisp around the edges. Remove from oven and sprinkle with sea salt. Let cookies cool on pans for a few minutes before transferring to a cooling rack.