Preheat oven to 325°F. Lightly grease your oven-safe skillet and set aside.

In a large bowl using a hand-held mixer or stand mixer fitted with a paddle attachment, beat the butter for 1-2 minutes on medium-high speed until smooth and creamy. Add the granulated sugar and brown sugar and beat on medium high speed until fluffy and light in color, about 2-3 more minutes. Beat in eggs and vanilla on high speed.

In a separate medium bowl, whisk the flour, oats, cornstarch, baking soda, cinnamon and salt together until combined. Slowly mix the dry ingredients into the wet ingredients on low speed until combined. The cookie dough will be thick, this is what you want. Add the chopped apples and M&M’S® Caramels and mix with a wooden or rubber spatula

Use a rubber spatula or wooden spoon to spread the cookie dough evenly into prepared skillet. Bake for 30-35 minutes or until puffed, browned on the sides, and lightly browned on top. Check half way through and cover gently with aluminum foil if over-browning. Allow the cookie to cool slightly in the pan set on a wire rack for 5-10 minutes.

Serve with ice cream and caramel sauce if desired.

Store and cover skillet cookie in the refrigerator for up to 5 days.