In a medium bowl, stir together all of the dry ingredients: 1 ½ cups all-purpose flour, 1 teaspoon cornstarch, ½ teaspoon baking soda, and ¾ teaspoon table salt.
In a large mixing bowl, stir the melted ½ cup unsalted butter, ¾ cup light or dark brown sugar, and ⅓ cup granulated sugar with a silicone spatula until smooth.
Add 1 egg and 1 tablespoon vanilla extract. Mix until smooth.
Dump in all of the dry ingredients and ¾ cup mini chocolate chips. Mix until no dry spots remain.
Shape & bake the mini cookies:
Preheat oven to 350°F/177°C and line two baking trays with parchment paper or silicone mats.
Use mini cookie scoop to scoop 1 tsp cookie dough balls. Place on lined baking sheet, about 3 inches apart. Repeat with remaining cookie dough.
Bake for 8-10 minutes, or until edges are set, cookies look lightly golden brown, and middles look very slightly underbaked. Don't worry—they will finish baking on the cookie sheet while cooling! Immediately sprinkle flaky sea salt on top.Optional: For rounder, more aesthetic cookies, take a something circular (cookie cutter, mug, cup) and larger than your cookies, and place it on top of a warm, freshly baked cookie. Move the circular object around to shape the edges of the cookie until it becomes rounder. Then, top with a few more mini chocolate chips.
Let cool on pan for about 5 minutes, then transfer to wire rack. Bake any remaining cookies. Enjoy!
Notes
Storage: Store cooled, freshly baked cookies in airtight container at room temperature for up to 1 week.
Tip for measuringingredients: I weigh my ingredients with a kitchen scale, rather than using measuring cups because it is more accurate. If using measuring cups, I recommend spooning flour into the cup and overfilling it, then leveling it off with a knife.