Vanilla Mug Cake

Ingredient:
2 tablespoons unsalted butter
1 tablespoon milk
½ teaspoon vanilla extract
1 large egg yolk* do not add in the egg white
2 tablespoons white sugar
4 tablespoons all-purpose flour
½ teaspoon baking powder
2 tablespoons unsalted butter
2-3 tablespoons powdered sugar
1 teaspoon milk
Optional: Sprinkles
Instructions:
Add the butter to your mug and microwave until melted (about 30 seconds).
Whisk in the milk, vanilla extract, egg yolk & sugar with a fork.
Then whisk in the flour and baking powder. Stir in the sprinkles.
Microwave for 60-90 seconds on medium power. The top should look set when it's done.
Cool for at least 1 minute before enjoying.
Optional: Spread/pipe frosting on top of the cake.