Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Place all ingredients in a mixing bowl. Mix until all ingredients are incorporated and mixture is smooth. Do not overmix.

Divide the batter between the three mugs. The batter should fill the mugs about three-quarters of the way. Place the mugs on a baking sheet. Bake for 40 minutes, or until a toothpick comes out clean.

Allow to cool completely before adding cream cheese frosting. If making these ahead of time, freeze without the frosting.

Place all ingredients in an electric mixer and mix on high speed for five minutes.

Place the frosting in a piping bag and pipe onto the top of the mug cake as you would froth milk or whipped cream.

For a coffee look, dust with a bit of cinnamon or cocoa. For a hot chocolate look, add mini marshmallows and chopped peppermint candies.