8ounces(227g) full fat block cream cheesesoftened to room temperature
½cup(113g) unsalted buttersoftened to room temperature
3 and ½cups(420g) powdered sugar
Preheat the oven to 350ºF (177ºC). Line a 12-count muffin tin with cupcake liners. Set aside.
In a medium size bowl with a handheld mixer or the bowl of a stand mixer fitted with the whisk attachment, whip the egg whites until soft peaks form (approximately 2 minutes). Set aside or remove from mixer bowl and transfer to a smaller bowl.
Sift the flour, cornstarch, cocoa powder, salt, and baking soda together into a medium size bowl. Set aside.
In a large bowl with a handheld mixer or the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugar together on medium speed until light and fluffy (approximately 2-3 minutes). Add the vegetable oil and beat again until completely incorporated. Add the egg yolks, vanilla extract, vinegar, and food coloring and beat again on medium speed until everything is combined.
Turn the mixer down to low speed and add the dry ingredients in three additions, alternating with half of the buttermilk. Do not overmix batter. Gently fold the whipped egg whites into the batter with a spatula.
Spoon batter evenly into the cupcake liners filling 1/2 to 2/3 of the way full (I like to use an ice cream scoop with a trigger-- one scant scoop full). Bake for 14-16 minutes or until a toothpick inserted in the center comes out clean. Be careful not to overbake, as red velvet tends to dry out a bit. Allow to cool in the pan for a few minutes, then transfer to a wire cooling rack to cool completely.
CREAM CHEESE FROSTING
In a large bowl with a handheld or the bowl of a stand mixer fitted with a paddle attachment, beat the cream cheese and butter together on high speed until smooth and creamy. With the mixer on low, add the powdered sugar, vanilla, and salt.
Increase mixer speed to medium-high and beat for 2 minutes.