Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans. Line the bottoms with parchment paper.

In a large bowl, whisk together the flour, sugar, baking soda, salt, and cocoa powder.

In a separate bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the eggs one at a time, then stir in the vanilla extract.

In a small bowl or liquid measuring cup, combine the buttermilk, purple food coloring, and white vinegar. Stir until well combined. The vinegar will react with the buttermilk, creating a slightly curdled appearance.

Alternately add the dry ingredients and the buttermilk mixture to the butter mixture, beginning and ending with the dry ingredients. Mix on low speed until just combined. Do not overmix.

Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.

In a large bowl, beat the softened cream cheese and butter until smooth and creamy.

Gradually add the powdered sugar, mixing until well combined and smooth. If the frosting is too thick, add milk or cream, one tablespoon at a time, until desired consistency is reached.

Stir in the vanilla extract.

Once the cake layers are completely cool, place one layer on a serving plate. Spread a generous amount of frosting over the top.

Carefully place the second cake layer on top. Frost the top and sides of the entire cake with the remaining cream cheese frosting.

Decorate as desired. Slice and enjoy your beautiful Purple Velvet Cake!