1. Soften the butter at room temperature for a smooth texture.
2. Beat the butter alone for a few minutes until light and fluffy.
3. Sift powdered sugar and cocoa powder to prevent lumps.
4. Gradually add the powdered sugar and cocoa powder to the butter, mixing well.
5. Pour in milk or cream, vanilla extract, and a pinch of salt.
6. Beat the mixture for several minutes until light and fluffy.
7. Adjust the consistency by adding more milk for a softer frosting or more powdered sugar for a firmer texture.
8. Optionally, add espresso powder to enhance the chocolate flavor.
9. Use immediately to frost cakes or cupcakes, or store for later use.
10. Refrigerate for up to one week or freeze for up to three months.
11. Before using refrigerated frosting, let it come to room temperature and rewhip for the best texture.
12. If desired, experiment with flavor variations like peppermint or almond extract.
13. For a richer frosting, use European-style butter with higher fat content.
14. Can be made dairy-free by using plant-based butter and milk.
15. If preferring melted chocolate, replace cocoa powder with melted chocolate for a different texture.