Preheat the oven to 325°F. Grease and flour three 9-inch cake pans, then line the bottoms with parchment paper.
In a bowl, sift together the flour, baking powder, baking soda, and salt. Set aside.
Using a mixer or whisk, blend the oil and eggs until well combined. Add the sugar and continue mixing until smooth.
Mix in the buttermilk and vanilla extract.
Gradually add the sifted dry ingredients to the wet mixture and stir until just combined; avoid overmixing.
Pour in the hot water and vinegar, stirring until fully incorporated.
Evenly distribute the batter among the prepared pans and bake for approximately 30 minutes or until a finger pressed lightly into the center springs back.
Let cakes cool in their pans for about 5-10 minutes before turning them upside down onto plastic wrap, a kitchen towel, or parchment paper. Leave the parchment paper on for now.
Once completely cooled, use a serrated knife to trim off any browned tops of the cake layers. Remove parchment paper from one layer and place it on your serving platter.
Spread one-fourth of the cream cheese frosting over this first layer before adding another layer of cake on top (removing its parchment paper as well).
Repeat with another fourth of frosting and place on the final cake layer after removing its parchment paper.
Use remaining frosting to cover the sides and top of your assembled cake. Decorate as desired using a piping bag fitted with a small round tip.