In a large bowl, beat the butter for a minute until smooth and creamy.
¾ cup unsalted butter
Add the sugars and beat on medium speed until fluffy and light in color.
¾ cup dark brown sugar, ¼ cup granulated sugar
Add the egg and vanilla.
1 large egg, 1 tablespoon vanilla extract
Mix all ingredients together.
In a separate bowl, combine the flour, cornstarch, salt, baking soda, and cinnamon.
2 cups all-purpose flour, 2 teaspoons cornstarch, 1 teaspoon baking soda, ½ teaspoon salt, 1 teaspoon ground cinnamon
Slowly add the dry ingredients to the wet ingredients and mix until completely combined.
Add in chocolate chips and mix just until combined throughout the dough.
1 ½ cup semisweet chocolate chips
Cover the dough tightly and chill for at least 2 hours and up to 2 days.
Let the dough sit at room temperature while the oven is preheating to 350°F and cover a baking sheet with parchment paper or a nonstick baking mat.
Roll cookie dough into balls, with about one tablespoon of dough for each one. Place the cookie balls on the cookie sheet about two inches apart from each other.
Bake for 8-9 minutes at 350°F, until just golden brown around the edges.
Let the cookies cool for five minutes on the cookie sheet.
Transfer them to cooling racks to allow them to cool completely or eat while warm.