2 and 1/4 cups (280 grams) all-purpose flour, measured correctly
1 teaspoon baking soda
1 and 1/2 teaspoons cornstarch
1/2 teaspoon salt
3/4 cup (1.5 sticks or 170 grams) unsalted butter, melted
3/4 cup (150 grams) light brown sugar, loosely packed
1/2 cup (100 grams) granulated sugar
1 large egg + 1 egg yolk*
2 teaspoons vanilla extract
1 cup (180 grams) chocolate chips or chocolate chunks
Take out a large bowl and toss in the flour, baking soda, cornstarch, and salt. Set aside. Next, take out a medium bowl and melt the butter. Then, whisk in the sugars and stir well. Next, whisk in the egg and egg yolk. Stir well. Finally, whisk in the vanilla. Stir well. Then, fold the wet mixture into the dry mixture and mix together. Now, fold in the chocolate chips. The dough will be very sticky because of the melted butter, but just try to get the chips as well incorporated as you can. Cover the dough with plastic wrap and chill for at least 2 hours and up to 3 days.
When you're ready to bake; take out the dough from the fridge and allow to soften for 15 minutes. Pre-heat your oven to 325, and line the cookie sheets with parchment paper or silpat. Roll the dough so they're taller rather than wider. Bake the cookies for 11-12 minutes. The cookies will come out of the oven looking soft and underbaked. Allow the cookies to cool on the cookie sheet for 10 minutes. Then, move cookies to wire rack to cool completely.