Preheat the oven to 350º F. Line a cookie sheet with a silicone baking mat or parchment paper.
In a mixing bowl combine the flour, cornstarch, baking soda, cinnamon and salt. Set aside.
In a larger mixing bowl combine the butter, brown sugar, and granulated sugar. Beat on medium speed for 2 minutes. You want this mixture to be fluffy and pale in color.
Add in the eggs and vanilla extract, beat for 30 seconds.
Gradually mix in the dry ingredients, mixing on low speed. The dough will be thick. I like to finish mixing the flour into the dough by hand with a spatula.
Use a cookie scoop to form golf ball sized cookie dough balls, roll into a smooth ball between your hands. Place about 8 cookies on a cookie sheet lined with a silicone baking mat at a time. I recommend only baking 1 cookie sheet at a time for even baking.
Bake the cookies for 10-12 minutes, then add the filling. Carefully remove the pan from the oven. Use the back of a tablespoon to create a well in the center of each cookie. Add about a tablespoon of filling to each cookie. Return to the oven and bake for 3-4 additional minutes. Allow the cookies to cool for 15 minutes on the baking sheet before removing. Drizzle with caramel sauce.