1. Preheat oven to 350°F and grease a 10- to 12-cup Bundt pan generously.
2. In a large bowl, whisk together the flour, baking soda, salt, and spices.
3. In another bowl, whisk the oil, eggs, brown sugar, granulated sugar, pumpkin puree, and vanilla extract until fully combined.
4. Pour the wet ingredients into the dry ingredients and mix until fully combined. Scrape the bowl sides and bottom to ensure even mixing.
5. Fold in chocolate chips or nuts if using.
6. Pour the batter into the prepared Bundt pan and spread evenly.
7. Bake for 55 to 70 minutes until a toothpick inserted near the center comes out clean or with a few moist crumbs.
8. Let the cake cool in the pan on a wire rack for 2 hours, then invert onto a serving plate.
9. Allow the cake to cool completely before adding frosting. For frosting, beat cream cheese, butter, and vanilla until smooth, add confectioners’ sugar, and mix until fully incorporated.