In a medium bowl, sift the flour, baking powder, baking soda, salt, and cornstarch.
1 ½ cups All-purpose flour, ¼ teaspoon Baking powder, ¼ teaspoon Baking soda, ½ tablespoon Cornstarch, ½ teaspoon Salt
In a large bowl, whisk the melted butter (make sure it is melted and cooled to room temperature first), sugar, vanilla, and eggs until smooth. Add in the dry ingredients and use a rubber spatula to mix until combined.
¾ cups White granulated sugar, 1 teaspoon Pure vanilla extract, 1 Large egg, ½ cup Unsalted butter
Preheat the oven to 350°F. Line two cookie sheets with parchment paper.
Use a small cookie scoop and scoop the cookie dough.
Mix the sugar and cinnamon in a small bowl. Roll the cookie dough ball into the cinnamon sugar. Place 12 cookie dough balls per cookie sheet. Use a 1 Tablespoon to make a hole in the middle of the cookie.
½ cup White granulated sugar, 1 teaspoon Ground cinnamon
Bake for 9-10 minutes. Bake until the cookies have lightly golden edges.
Let the hot cookies sit on the hot pans for 5 minutes before dipping the cookies into the cinnamon sugar. Let them cool completely before using the pumpkin pie filling.