1-First Step: Prepare Oven and Pans
Preheat your oven to 350°F (175°C), or 325°F if using coffee addition. Grease two 9-inch round cake pans and line the bottoms with parchment paper. Optionally, use cake strips for even baking.

2-Second Step: Mix Dry Ingredients
In a medium bowl, whisk together cake flour, baking soda, baking powder (if using), cocoa powder, and salt. Sifting ensures clump-free and well-mixed dry components.

3-Third Step: Combine Wet Ingredients
In a large bowl, beat softened butter and sugar on medium speed until fluffy. Add oil, then egg yolks (if separating eggs). Mix in vanilla extract and vinegar. Beat on high for about 2 minutes to incorporate air and develop volume.

4-Fourth Step: Create Buttermilk Mixture
In a liquid measuring cup, combine buttermilk, red food coloring, and hot brewed coffee (if using). This mixture contributes moisture and vibrant color to the batter.

5-Fifth Step: Combine Dry and Wet Ingredients
Alternately add dry ingredients and buttermilk mixture to the wet mixture on low speed start and end with dry. Mix only until combined to keep crumb tender. Scrape sides to ensure even mixing.

6-Sixth Step: Fold in Egg Whites
If using separated eggs, whisk egg whites to stiff peaks and gently fold into the batter for a light, smooth crumb.

7-Seventh Step: Bake the Cake
Divide batter evenly between prepared pans. Bake 30-35 minutes until a toothpick comes out clean or with moist crumbs. Start checking at 30 minutes as ovens vary.

8-Eighth Step: Cool the Cakes
Allow cakes to cool in pans for 10 minutes, then transfer to wire racks. Trim domed tops as needed for even layers before frosting.

9-Final Step: Frost and Serve
Beat cream cheese and butter until smooth and fluffy. Mix in vanilla and salt. Gradually add confectioners’ sugar and beat until creamy. Spread frosting between layers and all over cake. Chill 30-60 minutes before slicing for neat cuts and set frosting.