With a mixer, cream together the butter and sugar at medium speed. Add the vanilla and beat well. Add the flour and salt and mix until combined. Add the milk gradually until desired consistency is reached and beat until fluffy. Gently fold in chocolate chips. Frost cooled cupcakes. I like mine thick so I kind of spoon is on. Store in refrigerator.
Notes
Add less milk for a cookie dough to snack on or add more milk to make it into a dip!Source: Sally's Baking Addiction