Ingredients
- 2 tablespoons butter, softened
- 3 tablespoons sugar
- 1 egg yolk
- 2 tablespoons milk
- 1 teaspoon vanilla extract
- 5 tablespoons self-rising flour
- Pinch of salt
- 1/2 tablespoon rainbow or confetti sprinkles
- Frosting: (optional)
- 1 1/2 tablespoons butter, softened
- 1/4 cup powdered sugar
- 1/8 teaspoon vanilla
- Milk or water to achieve desired consistency
Preparation
Step 1
Lightly grease a 12-ounce microwave-safe mug and set aside. In a 2-cup microwave-safe measuring cup or bowl, microwave butter until just melted, about 10 seconds. Add sugar and stir. If mixture is hot, allow it to cool before adding egg yolk. Beat in egg yolk with a fork. Stir in milk and vanilla. Add flour, salt and sprinkles and stir until batter is smooth.
Pour batter into mug, filling it no more than halfway. Microwave for about 60 to 70 seconds, or about 10 to 15 seconds after cake has risen and peaked. Cake will fall and may appear wet, but should spring back to touch. If not done, microwave 10 to 15 seconds longer and check for doneness. Do not over cook or cake will become tough and spongy. Allow to cool slightly and set up before serving. Cake is best when enjoyed shortly after it's prepared.
For Frosting: (optional)
Stir together butter, sugar and vanilla. Add a few drops of milk or water at a time and stir well to achieve desired consistency. Alternatively, top with ice cream, if desired.