1. Preheat oven to 350°F (176°C) and prepare three 8 inch cake pans with non-stick baking spray and parchment paper in the bottom.
2. Combine the flour, baking powder, baking soda, spices and salt in a medium sized bowl and set aside.
3. Add the butter, sugar, and oil to and large mixer bowl and beat together until light in color and fluffy, about 3-4 minutes. Do not skimp on the creaming time.
4. Add the eggs two at a time, mixing until mostly combined after each addition. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated.
5. Add half of the dry ingredients to the batter and mix until mostly combined.
6. Add the vanilla extract and pumpkin puree and mix until well combined.
7. Add the remaining dry ingredients and mix until well combined and smooth. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated. Do not over mix the batter.
8. Stir in the chocolate chips.
9. Divide the batter evenly between the prepared cake pans and bake for 24-27 minutes, or until a toothpick comes out with a few moist crumbs.
10. Remove cakes from oven and allow to cool for 2-3 minutes, then remove to a cooling rack to finish cooling.
11. To make the chocolate frosting, add the butter to a large mixer bowl and beat until smooth.
12. Add the melted chocolate and mix until well combined.
13. Add the cocoa powder and mix until well combined.
14. Add about half of the powdered sugar, salt and half of the heavy cream and mix until well combined.
15. Add the remaining powdered sugar and mix until smooth.
16. Add the remaining heavy cream as needed to get the right consistency of frosting.
17. To layer the cake, first use a large serrated knife to remove the domes from the tops of the cakes so they are flat.
18. Place the first cake layer on a serving plate or on a cardboard cake circle.
19. Spread about 1 cup of frosting on top of the cake layer.
20. Add the second layer of cake and another cup of frosting.
21. Top the cake with the third layer and frost the top and outside of the cake with the remaining chocolate frosting. Refer to my tutorial for frosting a smooth cake, if you’d like.
22. Pipe shells onto the outside edge of the top of the cake.
23. Press some mini chocolate chips into the bottom edge of the cake.
24. Place a few candy pumpkins around the top of the cake, then add a few more mini chocolate chips.
25. Refrigerate cake in an air tight container. Serve at room temperature. Cake is best if eaten within 2-3 days.