For the Cake

1. Preheat the oven to 325°F . Prepare three 8-inch round baking pans, line the bottom with parchment paper, then grease and flour the pan.
2. In a large mixing bowl, combine the vegetable oil, butter, egg, and vanilla extract. Beat on medium speed until well incorporated. Next, add the sugar and beat until well combined. Scrape down the bowl as needed, Next mix add the sour cream, vinegar, buttermilk, and red gel color and beat until well combined.
3. In a separate bowl, combine and sift the remaining dry ingredients and add to the batter, beating at a low speed until well combined. Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed.
4. Divide the cake batter evenly between the three 8-inch pans, approximately 2 cups of batter per pan. Bake at 325°F for 28-32 minutes. Check the cakes for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, the cake is done. Allow the cake to cool in the pans for 15 minutes. Then gently run a knife around the edges of the cake and flip them out of the pan and onto a rack to cool completely.

For the Frosting

1. Cut the butter into pieces, about 1 tablespoon size. Using the paddle attachment, whip butter for 3-5 minutes, scraping down the bowl occasionally until the butter is light and fluffy. Then add the cream cheese and cream together with the butter for 2-3 minutes until they are whipped and free of lumps, scrape down the bowl occasionally.
2. Slowly add confectionary sugar, 3-4 cups at a time, alternating with the liquid (vanilla extract and milk), and beat until desired consistency is reached. Add the salt with the powdered sugar.

For the Assembly

1. Level the cake layers if needed. Place a dollop of frosting on your cake board and place the bottom layer of cake on top of that. Place 2 cups of frosting in a piping bag for the two layers. Pipe in circles working outside edge to the middle. Spread evenly with an offset spatula. Add the second layer of cake and add the remaining frosting. Place the third layer of cake on top, and invert the top layer.
2. Use the piping bag to fill in any gaps between the layers and to create a crumb coat. Using an offset spatula or icing smoother, wipe away the excess frosting, leaving just enough to coat the outside of the cake. Place it in the freezer for 5-10 minutes to chill.
3. With the remaining frosting, separate out at least 1 cup for decorating. Then proceed to frost the top and sides of the cake using an offset spatula. To add texture, turn an angled spatula 90 degrees, and gently press into the side of the cake, all the way around, working from the bottom to to the top. To pipe the rosettes on top, use an open star tip. Garnish the cake with leftover cake crumbs, gently pressing into the sides of the cake.