Preheat oven to 350 degrees F and grease and flour a bundt pan VERY well. (Instead, I suggest making a smooth mixture of equal parts of oil, shortening, and flour and then brush that on.)
In a small bowl, combine 1/4 cup of the flour with the chocolate and set aside.
In a large bowl, mix together the remaining flour, sugars, pumpkin pie spice, baking powder, baking soda, and salt. Make a well and set aside.
In a medium mixing bowl, combine all the wet ingredients: pumpkin, oil, and eggs. Add to the dry ingredients and mix until combined. Add the flour coated chocolate and stir until just combined. Pour into pan and bake for 60-70 minutes until toothpick comes out clean (mine took 70). Let it cool for 10 minutes before removing from pan. Allow it to cool 30 more minutes before applying the sauce.
Make the caramel sauce about 20 minutes after remove the cake from the pan. In a small pan, bring caramel sauce ingredients to a simmer until it begins to thicken (about 3 minutes). Remove from heat and let it sit for 5 minutes. Spoon over cake. Let cake cook completely before slicing.
Combine cream ingredients in a mixing bowl and beat with an electric mixer until it forms stiff peaks. Spoon or pipe onto pieces of cake and sprinkle with pumpkin pie spice. Serve.