Preheat oven to 350 F / 175 C and line a standard sized muffin tin with 12 cupcake liners.
In a medium-sized bowl, sift together the dry ingredients (cake flour, cocoa powder, baking powder, and salt). Set aside.
In a large bowl, cream together the butter and granulated sugar with either a hand mixer or a stand mixer fitted with a whisk attachment. Mix on a medium-high speed for about a minute. The mixture should become lighter in color.
Mix in the eggs on medium speed until fully incorporated. Scrape the sides and bottom of the bowl with a rubber spatula as needed.
Mix in the buttermilk, vegetable oil, vanilla extract, and food coloring on a low speed until combined and evenly colored.
Mix the dry ingredients into the wet ingredients in two installments on a low speed, mixing just until you can no longer see streaks of flour. Scrape the sides and bottom of the bowl with a rubber spatula as needed.
Divide the batter evenly between the cupcake tins and bake for about 17-20 minutes (or until a toothpick comes out with moist crumbs).
Remove the cupcake pan from the oven and allow it to cool in the pan for 10 minutes. Carefully remove the cupcakes from the pan and place them on a wire rack to finish cooling.