Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans.
In a large mixing bowl, combine the flour, sugar, cocoa powder, and salt.
In another bowl, mix the vegetable oil, buttermilk, eggs, food coloring, and vanilla extract until well combined.
Gradually add the wet ingredients to the dry ingredients, mixing until just combined.
In a small bowl, combine the baking soda and vinegar, then quickly fold into the batter.
Divide the batter evenly between the prepared pans.
Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer to wire racks to cool completely.
For the frosting, beat the cream cheese and butter together until smooth.
Gradually add powdered sugar and vanilla, mixing until creamy and fluffy.
Once the cakes are completely cool, frost the top of one layer, place the second layer on top, and frost the top and sides.