Combine all ingredients in a coffee cup; stir to fully incorporate.
Using a milk frother on an expresso machine: Steam until milk is fully heated and frothy on top. Using a hand frother: Heat the milk mixture in a microwave on high until fully heated (1 ½-2 minutes depending on the microwave), insert the frother into the cup and froth until bubbly on top. Microwave: Heat on high for 1 ½-2 minutes until the milk is heated through and frothy on top.