1. Preheat oven to 350 degrees F. Mix flour, cocoa powder, baking soda and salt in medium bowl. Set aside.
2. Beat butter and sugar in large bowl with electric mixer on medium speed for 5 minutes or until light and fluffy. Beat in eggs, one at a time. Mix in sour cream, milk, food color and vanilla. Gradually beat in flour mixture on low speed until just blended. Do not overbeat. Spoon batter into 30 paper-lined muffin cups, filling each cup 2/3 full.
3. Bake 20 to 25 minutes or until toothpick inserted into cupcake comes out clean. Cool in pans on wire rack 5 minutes. Remove from pans; cool completely
1. Cream butter and shortening for 3 minutes at medium high speed, scrape the sides then mix again for 1 minute.
2. Gently add icing sugar till well combined, mix for 3 minutes at medium high speed.
3. Add milk, egg white powder and salt to the mixture. Mix again for 3-4 minutes at medium high speed till cream achieves its consistency. Don’t forget to scrape the side of the bowl.