In a bowl combine room temperature brown butter with granulated and brown sugar. Whisk to combine.
Add eggs one at a time mixing well after each addition. Add the vanilla extract and mix for a minute until the eggs are fully blended with the butter and sugar.
Sift flours, baking soda, cream of tartar, salt, and cornstarch and add to the butter mixture.
Mix together just until the dough comes together.
In lightly buttered 8 inch cast iron skillet or round metal pan, press half of the cookie dough onto the base and an inch up the sides of the pan.
Spoon apple pie filling in the center making sure to keep the filling away from the elevated edges of the cookie dough.
Taking small handfuls of remaining cookie dough, press flat in between your palms and gently lay on top of the filling.
Pinch and press the cookie dough on top to connect it into one large piece over the top of the filling. Pinch the edges of cookie dough closed around the edges of the pan. It doesn't have to be perfect some gaps are ok.
Combine sugar and cinnamon in a small bowl on sprinkle evenly on top of the cookie pie.
Bake in a 350*F oven for 30 minutes. The top should be lightly browned and set. Do not overbake as the dough will continue to cook from the residual heat of the cast iron.
Allow to cool for 10 minutes before serving. Caramel sauce and ice cream is highly recommended.
Enjoy!