Preheat oven to 325°F. Grease a 9x13-inch baking dish.
Beat cream cheese until smooth, then mix in oil and sugar.
Add eggs one at a time, mixing well after each. Stir in vanilla.
In a separate bowl, whisk flour, baking powder, and salt. Gradually mix into the wet ingredients.
Stir in buttermilk until batter is smooth—don’t overmix.
Pour into the baking dish and bake for 35–40 minutes, or until a toothpick comes out clean. Let cool completely.
For the frosting: Beat cream cheese and butter until smooth. Add vanilla and salt. Gradually add powdered sugar until you get a thick, spreadable consistency.
Frost cooled cake, then refrigerate for at least 30 minutes before serving. Enjoy chilled!
