In medium mixing bowl, stir together Cocoa Powder and Confectioner's Sugar with a whisk until well combined and large clumps are broken up.
Using mixer, cream the Butter until smooth.
Pour Cocoa/Sugar mixture into the bowl with creamed butter, and continue mixing on low speed.
Add in Vanilla and gradually add in Milk, and mix first on low, then on medium speed until you reach your desired consistency.* You'll want to scrape down the sides and bottom of your bowl with a spatula to make sure everything gets well combined.
Then once done mixing, stir well again with spatula to break up any air bubbles.
Immediately frost on your cooled cake or pipe onto your cooled cupcakes.
Then enjoy your frosted treats right away, and store any leftovers in the refrigerator. ENJOY!
Notes
*For thicker frosting use less milk, and for thinner frosting you can add a bit more milk as neededRecipe can be easily doubled for larger multi-layer cakes or big batches of cupcakes.Use these tips for How To Soften Butter Quickly!