1-First Step: Setup and mise en place Preheat the oven to 350°F (177°C). Line a standard 12 or 14-cup muffin pan with liners. Measure all ingredients precisely and bring eggs, butter, and buttermilk to room temperature. This helps everything blend smoothly and bake evenly.

2-Second Step: Whip the egg whites Separate 2 large eggs. Using a clean bowl and whisk or electric mixer, whip the 2 egg whites to soft peaks and set aside. The whipped whites add lift and a lighter crumb when folded in later. Avoid over-whipping.

3-Third Step: Combine dry ingredients In a medium bowl, whisk together 1 and 1/3 cups all-purpose flour, 1/4 cup cornstarch, 1/2 teaspoon baking soda, 4 teaspoons natural unsweetened cocoa powder, and 1/4 teaspoon salt until well mixed and aerated.

4-Fourth Step: Cream butter and sugar Cream 1/4 cup unsalted butter until smooth, then add 1 cup granulated sugar and beat for about 2 minutes until lighter in color. This aerates the mixture and builds the base structure for the cupcakes.

5-Fifth Step: Add oil and yolks Slowly add 1/2 cup canola or vegetable oil to the butter-sugar mix and mix briefly. The batter may look slightly piece-y; that is normal. Mix in 2 egg yolks, 2 teaspoons pure vanilla extract, 1/2 teaspoon distilled white vinegar, and the desired amount of red food coloring (about 2 tablespoons for dark red). Mix until the color is even.

6-Sixth Step: Alternate dry and wet additions Alternate adding the dry ingredient mixture and 1/2 cup buttermilk in three parts, starting and ending with the dry ingredients. Stir gently and mix only until just incorporated; over-mixing develops gluten and can make cupcakes tough.

7-Seventh Step: Fold in whipped egg whites Use a spatula to gently fold the whipped egg whites into the batter in two additions, keeping as much air in the batter as possible. Folding gently preserves lift and helps create a fluffy texture.

8-Eighth Step: Fill liners and bake * Fill cupcake liners halfway to two-thirds full using a 1/4-cup scoop or ice cream disher for uniform sizes.
* Bake at 350°F (177°C) for 20-21 minutes or until a toothpick inserted in the center comes out clean.
* For mini cupcakes, bake 12-13 minutes. For larger pans, adjust time accordingly and test early.

9-Ninth Step: Cool and frost Cool cupcakes in the pan for 5 minutes, then transfer to a wire rack to cool completely. Top with cream cheese frosting just before serving. If you need to chill frosting, refrigerate it and bring it back to spreading consistency before topping.