Preheat oven to 350°F. Generously butter and flour 10-cup bundt cake pan. Tap out excess flour. Set aside. In the bowl of a stand mixer fitted with a paddle attachment (or using a handheld mixer, cream together butter, oil, sugar, molasses, and vanilla. Scrape down bowl as needed.
Add eggs one at a time, ensuring each egg is incorporated before adding the next. Mix on medium speed until well blended.
In a large bowl, whisk together flour, baking power, baking soda, salt, and spices. Set aside.
Add the dry flour mixture in three additions, alternating with the pumpkin puree. Begin and end with the flour mixture. Mix on low speed until thoroughly combined. Scrape down bowl as needed to ensure even mixing.
Pour batter into prepared bundt cake pan. Level batter. Bake for 55-65 minutes until cake springs back to touch and a toothpick inserted in cake comes out clean.
Allow cake to cool in pan for 10-15 minutes. Invert bundt cake onto a wire rack. Unmold and cool cake to room temperature.