Yellow Cupcakes with Chocolate Frosting

In our house we need no reason nor rhyme to make a dessert.This is the frosting we love best as it has sour cream which adds some sourness and the mix of sweet and sour is something that is liked by all of us. My husband especially so, as he doesn't typically like sweets which are all too sweety. With this frosting on top of the traditional cup cakes makes a very tasty treat, I am sure would be well liked by all.
Source:http://www.daisybrand.com/
Chocolate Frosting
Serves: 12
Ingredients
 Butter, softened-1/2 cup
 Unsweetened cocoa powder-2/3 cup
 Vanilla extract-1 teaspoon
 Powdered sugar-3 cups
 Milk-1/4 cup
 Daisy Brand Sour Cream-1/4 cup
Method:
In a medium bowl, beat the butter at high speed until creamy (1 to 2 minutes). Add the cocoa powder and vanilla; continue beating, scraping the bowl often, until the mixture is creamy (1 to 2 minutes). Add the powdered sugar, 1 cup at a time, beating well after each addition. Add the milk and ¼ cup sour cream; continue beating, scraping bowl often, until creamy (1 to 2 minutes). Refrigerate leftovers.
Ingredients
Butter-1/2 cup or 1 stick
Sugar-3/4 cup
Egg yolks-4
Milk-3/8 cup(half of 3/4 cup)
Vanilla extract-3/4 teaspoon
Cake flour-1cup
Baking powder-1teaspoon
Salt-1/4 teaspoon
Method:
Preheat oven to 350 degrees F (175 degrees C). Line a muffin pan with paper or foil liners. Sift together the flour, baking powder and salt. Set aside.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the egg yolks one at a time, then stir in the vanilla. Beat in the flour mixture alternately with the milk, mixing just until incorporated. Pour batter into prepared pans.
Bake for 15 to 17 minutes in the preheated oven, or until a toothpick inserted into the cake comes out clean.When cool frost them with the frosting.