Preheat oven to 350 degrees F. Grease and flour 2 9 inch round cake pans.
On a large parchment paper, sift the flour, sugar, baking soda, salt and cocoa powder together. This is the dry mixture.
In a stand mixer bowl, mix the oil, buttermilk, eggs, food coloring vinegar and vanilla extract.
Gently mix the dry ingredients into the dry until it’s all combine together.
Divide the batter evenly between 2 pans. Bake for about 30 minutes or until when the toothpick inserted into the middle of the cake comes out dry.
Cool the cake for 5 minutes on a cooling rack. Invert the cake and cool completely on a cooling rack.
Ermine Cream Cheese Frosting
In a small saucepan, whisk together flour, milk, and salt. Bring to a boil over medium heat and whisk constantly. As it becomes thicker like a roux, you want to keep whisking until it comes together.
Take the pan off the heat and add the vanilla extract. Whisk until the vanilla is mixed in. If it is clumpy, you can put it through a sieve.
Put into a small bowl. Put a plastic wrap directly on top of the mixture so it doesn’t form a skin. Cool completely.
In the bowl of a stand mixer, cream the butter, cream cheese and sugar for about 5 minutes on medium high speed until the mixture becomes smooth.
Add a tablespoon at a time, the cooled roux. Keep mixing the frosting on medium high speed for about 2-3 minutes until it is combined. Refrigerate before using because it is a very soft frosting.