Preheat your oven to 325 degrees F.

In a large bowl or bowl of a stand mixer, cream together the butter, cream cheese, and white and brown sugars.

Add vanilla, egg, and egg yolk and mix to combine.

Add sour cream and mix.

Add cinnamon, baking soda, salt, cornstarch, and flour, and mix until a dough forms.

Scoop the cookie dough with a 2 tbsp scoop onto a half sheet tray, 12 per tray.

Roll the scoops into balls and roll them into the 2 tbsp of sugar for rolling.

Bake for 13-15 minutes, or until crinkly and the edges are just beginning to crisp.

Add the diced apples to a saucepan with brown sugar, cinnamon, butter, salt and vanilla.

Cook over medium heat until tender and bubbly.

Add the cornstarch slurry and cook until glossy, about 30 seconds more.

Remove the apple filling from heat.

For the buttercream, add butter, cream cheese, vanilla, and salt to a bowl and whip to combine.

Add the powdered sugar, alternating with cream as needed, to reach a smooth frosting.

Scrape down the bowl and mix in the dulce de leche.

Add more salt as needed to taste.

Transfer the buttercream to a piping bag.

Frost each cooled cookie with a swirl of buttercream, a drizzle of dulce de leche, and about a teaspoon of the cooled apple pie filling.