- Preheat the oven to 350°F. Lightly grease a 9- or 10-cup Bundt pan.
- In a large bowl, use an electric mixer to beat the butter and sugars at medium speed for about 2 minutes. The mixture will be light and airy, and will have lightened in color. For a visual, see our video, how to cream butter and sugar.
- Add the eggs one at a time, beating for a minute or two between additions. Scrape the sides and bottom of the bowl, and beat briefly to recombine any residue.
- Add the baking powder, salt, and baking soda, then gently beat in half the flour.
- Gently mix in the sour cream and vanilla, then add the remaining flour, mixing just until blended.
- Scoop the batter into the prepared pan, and bake for 55 to 60 minutes, until a cake tester or toothpick inserted in the center comes out clean.
- Remove the cake from the oven. Cool it in the pan for 15 minutes before turning it out of the pan onto a rack to finish cooling. Cool completely before slicing.