In a large mixing bowl, using a hand mixer, cream the butter, brown sugar, and 5 tablespoons granulated sugar together until fluffy, about 3 minutes.
1 cup unsalted butter, 1 cup brown sugar, 5 tablespoons granulated sugar
Mix in the eggs and vanilla until combined.
2 large eggs, 2 teaspoons pure vanilla extract
In a separate bowl, whisk the flour, ½ tablespoon cinnamon, baking soda, cornstarch, and salt together.
2¾ cups all-purpose flour, 1 teaspoon baking soda, 1 teaspoon cornstarch, ½ teaspoon kosher salt, 0.5 tablespoon ground cinnamon
Beat the dry ingredients into the wet ingredients just until combined and dough starts to come together. Do not overmix.
In a separate small bowl, stir together the remaining 4 tablespoons granulated sugar and ½ tablespoon cinnamon.
4.01 tablespoons granulated sugar, 0.5 tablespoon ground cinnamon
Line a baking sheet with parchment paper.
Using a 2-tablespoon-sized cookie scoop, scoop cookie dough batter and drop each raw cookie (one at a time) into the cinnamon-sugar mixture. Roll cookie dough ball around until fully coated in cinnamon sugar then use hands to shape into smooth round balls (do not flatten). Place each cookie onto the lined baking sheet. They can stay close together (but not touching) until ready to bake.
Place raw cookies into freezer for 10 minutes.
While the cookies chill, preheat oven to 350°F and line a second baking sheet with parchment paper.
Remove some of the cookies from the freezer and place on the prepared baking sheet with cookies about 2 inches apart from each other.
Bake cookies for 12-14 minutes, or until bottoms of cookies are set.
Let the cookies cool on the baking sheet completely before enjoying.