Step 1

Mix the Dough: In a large mixing bowl, cream together softened butter, light brown sugar, and granulated sugar using either a hand mixer or a stand mixer with the paddle attachment. Cream them until the mixture becomes light and fluffy, which should take around 2 minutes.

Step 2

Incorporate the Wet Ingredients: Add the large egg and pure vanilla extract to the mixture. Beat them for about one minute or until fully combined. Set this mixture aside.

Step 3

Add the Dry Ingredients: Sprinkle in the all-purpose flour, cornstarch, baking powder, baking soda, and salt. Mix on medium until combined. The dough will be thick, which is exactly what you want for these cookies.

Step 4

Add Chocolate Chips and Walnuts: Gently fold the semi-sweet chocolate chips and walnut pieces into the dough using a wooden spoon. Avoid over-mixing to maintain a gooey texture.

Step 5

Chill the Dough: Refrigerate the dough for about 30 minutes. This step helps the cookies keep their shape and allows the flavors to meld.

Step 6

Meanwhile preheat the oven: While the dough chills, preheat your oven to 475°F. This high temperature ensures a perfect cookie texture, crispy on the outside and gooey on the inside. Line a large baking sheet with parchment paper. This step prevents the cookies from sticking and makes cleanup a breeze.

Step 7

Form Cookie Dough Balls: Once the dough is chilled, scoop out 2 heaping tablespoons of dough and roll each portion into a ball. Place these dough balls on the prepared baking sheet, leaving about 2 inches of space between each.

Step 8

Bake the Cookies: Bake for 7-8 minutes, or until the cookies are lightly browned on the outside and half-baked and gooey on the inside. The high oven temperature ensures this perfect texture.

Step 9

Cool and Enjoy: Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a cooling rack. You can let the cookies cool for another 5-10 minutes before indulging in these gooey chocolate chip cookies. They are at their gooey best when still warm.