Preheat the oven to 350 degrees F. Using the extra vegetable oil, lightly grease three 9-inch round cake pans, then using the extra flour, lightly dust the greased pans.
In a large bowl, sift together the flour, the sugar, the baking soda, the salt, and the cocoa powder.
In another large bowl, whisk the buttermilk, the remaining 1 1/2 cups of the vegetable oil, the eggs, the food coloring, 1 teaspoon of the vanilla, and the vinegar together.
Using a standing mixer, mix the dry ingredients into the wet ingredients until just combined, forming a smooth batter, but careful not to overmix.
Evenly divide the cake batter among the prepared cake pans.
Place the pans in the oven evenly spaced apart from each other in the oven.
Bake until the cakes detach away from the side of the pans, and a toothpick inserted into the center of the cakes comes out clean, about 30 minutes, rotating the pans halfway through cooking.
Remove the cakes from the oven and run a knife around the edges to loosen them from the sides of the pans.
Invert the cakes onto a plate and then place them onto a cooling rack, rounded sides up. Let them cool completely.
While the cake cools, in an electric stand mixer fitted with the paddle attachment, or with a hand-held electric mixer in a large bowl, mix the confectioners' sugar, the cream cheese, and the butter on low speed until incorporated.
Increase the speed to high, and mix for about 5 minutes, until light and fluffy.
Reduce the mixer speed to low.
Add in the remaining vanilla.
Raise the speed to high and mix until fluffy, about 2-3 minutes.
Before using, store in the refrigerator until it is slightly stiff.
Place 1 of the cakes, rounded-side down, in the middle of a rotating cake stand.
Using an offset spatula or palette knife, spread some of the cream cheese frosting over the top of the cake, making sure to spread enough of the frosting to make a 1/4-1/2-inch layer.
Gently set 1 of the remaining cake layers on top, rounded-side down, and repeat the frosting.
Top with the remaining cake layer and cover the whole cake with the remaining frosting.
Top the cake with the pecans.
Serve!