Position a rack in the center of your oven and preheat to 350°F. Generously butter and flour a 12-cup Bundt pan, tapping out excess flour, or use baking spray with flour.

In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, ginger, nutmeg, and salt until well combined.

In a large bowl, beat the softened butter, granulated sugar, and brown sugar on medium-high speed until light and fluffy, about 3 to 4 minutes. Scrape down the bowl as needed.

Beat in the eggs one at a time, mixing well after each addition. Add the pumpkin puree, sour cream, and vanilla extract. Mix on medium speed until just combined - the batter will look slightly curdled, which is normal.

Add the dry ingredients in three additions, mixing on low speed until just barely combined. Do not overmix. Use a rubber spatula to give the batter a final fold, scraping the bottom of the bowl to ensure no dry pockets remain.

Spoon the thick batter into the prepared pan and smooth the top with an offset spatula. Bake for 50 to 55 minutes, until a toothpick inserted into the center comes out clean and the cake springs back when lightly pressed. The top will be deeply golden.

Cool in the pan on a wire rack for 15 minutes, then invert onto the rack and carefully lift off the pan. Let cool completely, at least 1 hour, before slicing. The cake slices most cleanly when fully cooled.