1-First, preheat your oven to 350°F (175°C) and line an 8×8-inch baking pan with parchment paper for easy removal.

2-In a medium bowl, whisk together the flour, cornstarch, baking soda, and salt; set this aside to keep your dry ingredients ready.

3-Next, in a large bowl, combine the melted butter and sugars, whisking for about 30 seconds until thickened.

4-Then, add the eggs and vanilla extract to the butter mixture, whisking well for about 1 minute to incorporate everything evenly.

5-Stir the dry mixture into the wet ingredients using a silicone spatula until almost combined, leaving a few dry streaks for the best texture.

6-Reserve about ¼ cup of the chocolate chips and mix the rest into the dough before transferring it to the prepared pan.

7-Spread the dough evenly in the pan with an offset spatula and sprinkle the reserved chocolate chips on top for a nice finish.

8-Bake for about 55 minutes until the edges are set and golden brown, checking with a toothpick that comes out with a few moist crumbs.

9-Finally, let the bars cool in the pan for about one hour before removing and cutting into squares.