Preheat the oven to 350 F. Butter and flour a 10-cup bundt pan, making sure to tap out the excess flour.
Place the butter, sugar, vanilla extract, and salt in the bowl of a stand mixer fitted with the paddle attachment. Beat on medium-high speed for a couple minutes until the mixture is thick, fluffy, and very pale. Scrape down the sides once or twice with a spatula to get an even mix.
While the mixer is going, sift the flour and baking soda together into a large bowl.
Lightly beat the eggs in a medium bowl until blended, then gradually add them to the butter mixture. Add a tablespoon of flour with each addition of egg to prevent the batter from curdling. Beat the batter until well blended, scraping down the sides as needed.
Add half of the sour cream to the batter, then stir on low speed for about 5 seconds. Add half of the flour mixture and mix again for 5 seconds. Repeat until all the sour cream and flour is added to the batter.
Fold the batter by hand for a few seconds to make sure the mixture is evenly blended, then beat on high speed for 3 seconds.
Gently pour the batter into the prepared bundt pan and smooth the top.
Bake at 350 F for about 1 hour to 1 hour 15 minutes, until the pound cake has a golden brown dome with a crack on top. It is done when a wooden toothpick or skewer inserted into the crack comes out clean.
Let it cool for 5 minutes in the pan, then turn it out onto a wire rack and let it cool for about 30 minutes before slicing. Serve with whipped cream and fresh berries.