In a large bowl, using an electric mixer, beat together cream cheese, butter, vanilla, and milk until smooth and fluffy.
Add cocoa powder and powdered sugar (one cup at a time) and continue to beat on low speed until frosting is smooth and the desired consistency. Add more powdered sugar or milk if needed - sugar will thicken the frosting, milk will thin it.
Video
Notes
Store in fridge
Photos depict use of dark cocoa powder, any type will work
Makes enough for thick frosting on a 9x13 cake, a 2 layer cake, or about 24 cupcakes.