Preheat oven to 375 degrees F. Lightly grease 10-inch cast iron skillet.

In bowl of stand mixer with paddle attachment, add butter, brown sugar and granulated sugar. On medium-high speed, beat 3–4 minutes until light and fluffy. Stop to scrape sides of bowl with spatula.

To bowl of stand mix with butter/sugar mixture, add pumpkin puree, egg and vanilla extract and mix on low until combined. Then add flour, baking soda, salt and spices and mix on low until combined.

Remove bowl from mixer and fold in chocolate chips and chopped pecans.

Spread batter evenly into prepared skillet.

In medium mixing bowl, whisk together all pecan pie topping ingredients except pecan halves.

Across top of cookie, sprinkle pecan halves and pour pecan pie topping evenly.

Bake 25-30 minutes, until toothpick inserted in center comes out clean and edges are browned. (Note: The longer the cookie bakes, the more cake-like it becomes.)

Remove to baking rack to cool 15 minutes. Slice and serve warm on plates or in bowls. Serve with whipped cream or ice cream, if desired.