Preheat oven to 350°F.
Grease and lightly flour three 9 x 2-inch round cake pans, then line the bottoms with parchment paper.
In a small bowl, sift the cake flour, baking soda, salt and set aside.
In a large bowl, on the medium speed of an electric mixer, cream the butter and sugar until very light and fluffy, about 5 minutes.
Add the eggs, one at a time,beating well after each addition.
In a small bowl, whisk together the red food coloring, cocoa, and vanilla. Add to the butter mixture and beat well.
Add the buttermilk to the batter in three parts, alternating with the cake flour. With each addition, stir until the ingredients are incorporated, but do not overheat.
Using a rubber spatula, scrape down the batter in the bowl, making sure the ingredients are well blended and the batter is smooth.
Divide the batter among the prepared pans.
Bake for 30-40 minutes, or until a cake tester inserted in the center of the cake comes out clean. Let the layers cool in the pans for 10 minutes. Remove from the pans and cool completely on a wire rack.
When the cake has cooled, spread the frosting between the layers, then the ice top and sides of the cake with frosting.