Preheat the oven to 350 degrees F. Lightly butter a 10-inch cast iron skillet.
In a large bowl, whisk together the flour, nutmeg, cinnamon, ginger, allspice, cloves, baking soda, and salt.
In a medium bowl, cream together the brown sugar and butter with an electric mixer until smooth.
Whisk in the egg, pumpkin and molasses until blended well.
Slowly stir the dry ingredients into the butter mixture. The mixture will be very thick, use a fork or your hands to blend well. Fold in the chocolate chips.
Evenly spread the dough into the skillet.
Bake 25 to 35 minutes or until the edges are set and the center is slightly soft/gooey. Be careful not to over bake as it’s best to keep it moist.
Let cool to warm. Cut into wedges and top with caramel topping and roasted walnuts, if desired.
