Step 1: Preheat your oven to 350°F (175°C).
Step 2: In a medium bowl, whisk together 2 3/4 cups of all-purpose flour, 2 teaspoons of cornstarch, 1 teaspoon of baking soda, 3/4 teaspoon of salt, and 1/2 teaspoon of baking powder. Set aside.
Step 3: In a large mixing bowl, beat 1 cup of unsalted butter with 1 3/4 cups of granulated sugar using an electric mixer until light and fluffy (about 3-4 minutes).
Step 4: Add 1 large egg, 1 large egg yolk, and 1 tablespoon of pure vanilla extract to the butter-sugar mixture. Beat until well combined.
Step 5: Gradually add the dry ingredient mixture to the wet mixture, mixing on low speed until just combined.
Step 6: Gently fold in 1 cup of mini chocolate chips to the dough.
Step 7: Using a cookie scoop, portion out the dough and roll each piece into a ball, rolling in 1/3 cup of granulated sugar to coat lightly.
Step 8: Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden. Sprinkle flaky sea salt on top if desired.
Step 9: Let cookies cool on the baking sheets for 5 minutes before transferring to a cooling rack.
