Preheat oven to 350 degrees. Line two 12-cup muffin tins with cupcake papers.
Sift together the cake flour, baking powder, and salt into a medium bowl; set aside. In a small bowl, mix food coloring and cocoa powder to form a thin paste without lumps; set aside.
In a large bowl, using a hand mixer or stand mixer, beat butter and sugar together until light and fluffy, about three minutes. Beat in eggs, one at a time, then beat in vanilla and the red cocoa paste, scraping down the bowl with a spatula as you go. Combine the buttermilk and oil. Alternately add the flour mixture & buttermilk mixture to the butter mixture.
In a small bowl, mix vinegar and baking soda… it will fizz! (Fun!) Add vinegar mixture to the cake batter and stir well to combine. Using an ice cream scoop, fill cupcake cups with cake batter (they should be 2/3 – 3/4 full). You may not fill all the cups, I ended up with 20 cupcakes. Place muffin tins on the middle rack of a preheated 350 degree oven. Bake for approximately 20-22 minutes, rotating pans halfway through. Cupcakes are done when a toothpick inserted in the center comes out clean. Check early and don’t overbake!
Cool the cupcakes in their tins for 2 minutes, then transfer to a wire rack for 10-15 minutes, allow to cool completely before frosting. Frost cupcakes with your favorite cream cheese frosting or butter-cream frosting.
Top Red Velvet Cupcakes with shredded coconut, Red Dots, white non-pareils, and crushed candy canes. Eat up!