Preheat oven to 350°F with racks in the center of the oven. Grease two 9-inch cake pans with butter and dust with flour, tapping out the excess.
Stir then sift together 2 1/2 cups flour, 2 Tbsp cocoa powder, 1 tsp baking soda, and 1/2 tsp salt.
In a bowl with an electric mixer, beat together 1/2 cup softened butter and 1 1/2 cups sugar for a few minutes until sugar is moistened and the mixture looks powdery like snow. Mix in two eggs, adding them one at a time, and beating well to incorporate between each addition. Beat in 2 tsp vanilla extract until blended. With the mixer on, gradually add 3/4 cup oil and mix on medium speed until well incorporated.
Stir 1 tsp vinegar into your 1 cup buttermilk, then mix it into the batter on medium speed until incorporated.
Add flour mixture all at once and mix on medium speed just until well blended and no streaks of flour remain, scraping down the bowl as needed.
Add 1/2 tsp red gel food coloring (add more to reach the desired color) and mix just until blended, scraping down the bowl as needed.
Divide batter evenly between prepared 9-inch pans and bake at 350°F for 30 minutes. Let rest in cake pans for 20 minutes then invert onto a wire cooling rack and let cool completely to room temp before assembling with Cream Cheese Frosting.
Notes
Make-Ahead and Storage Tips:
To Refrigerate: Fully assemble and refrigerate this cake for up to 4 days.
Freezing a Whole Cake: You can freeze a fully assembled cake in a cake box (cover the box with foil to prevent freezer burn) for up to two months.
Freezing Cake Layers: Cool cake layers to room temperature then place plastic wrap or parchment paper between layers to prevent sticking. Wrap completely in plastic wrap and a layer of foil.
To Thaw: Thaw a fully assembled cake or cake layers in the refrigerator overnight. If you thaw it on the counter, you will end up with soggy cake. Bring to room temperature for 2 hours before serving.