Preheat the oven to 325 degrees F. Grease and flour a large bundt pan very well.
In a large mixing bowl, add the flour, salt, baking powder and baking soda. Whisk well and set aside.
In another bowl, add the buttermilk, vanilla extract and vegetable oil. Whisk well and set aside.
Add the butter and sugar to a large mixing bowl and mix on medium-high for 3-4 minutes until light and fluffy.
Add the eggs, one at a time, mixing on medium speed for about 15-20 seconds after each egg.
Alternately add in the dry mixture and the liquid mixture to the butter mixture, starting and ending with the dry mixture.(Add in ⅓ of the dry mixture and mix on medium just until combined. Add in ½ the liquid mixture, mixing on medium only until combined. Add in another ⅓ of the dry mixture, mixing on medium only until combined. Add in the last of the liquid mixture, mixing on medium only until combined, then the last of the dry mixture and mix until combined.) Be very careful only to mix until well combined. Mixing too long and at too high of a speed can cause the cake to come out dense, rubbery or to fall in the middle.
Scrape down the sides of the bowl and mix again only for 7-10 seconds or so.
Pour the batter into the prepared pan and bake at 325 degrees F for approximately 1 hour 10 minutes to 1 hour 20 minutes. (Mine takes about 1 hour 15 minutes.) Please note that ovens vary so you may need to bake a little more.
Cake is done when it is golden brown on top and a toothpick inserted into the cake, comes out with a few moist crumbs on it or clean, but no raw batter. Be careful not to over-bake or the cake could turn out dry. If the toothpick comes out with a few moist crumbs on it and no raw batter, go ahead and take it out. It's not necessary for the toothpick to come out completely clean. Sometimes waiting for that can cause an over-baked cake. Moist crumbs on the toothpick are fine, it just should not have any raw batter on it.
Once the cake is baked, set it, still in the pan, on a wire rack to cool for about 10 minutes, then remove from the pan and allow it to cool completely on the cooling rack or a cake plate.
See note section for how to store this cake, how long it should last, more ways to serve this cake plus other FAQs.