In a small bowl, pour in milk and 2 tbsp of fruity pebbles. Gently push the fruity pebbles until they are completely soaked in the milk. Heat your cereal up for about 20 seconds. Drain out cereal with a strainer. You should be left with 3 tbsp or slightly over 3 tbsp of cereal milk.
Take 3 tbsp of the cereal milk and add into a microwave-safe mug. This cake is about the size of a cupcake so your mug should hold at least 8 oz of liquid. If your mug is much bigger, that is fine, but your cake won't rise as high in your mug. Add in flour, sugar, baking powder and oil. Using a mini whisk, mix until batter is completely smooth and no flour lumps remain.
Stir in 1 tsp of fruity pebbles. Sprinkle additional 1 tsp of fruity pebbles over top of the cake. Cook cake in microwave for about 1 minute at full power. Let cool a few minutes before eating.
Notes
You can use other types of cereal, but if you use less sugary cereals, you may need to add more sugar to the batter, or if you use more sugary cereals, you might want to reduce the amount of sugar added to the batter.
Also, different cereals may yield different taste results. I found that fruity pebbles quickly changed the milk to a fruity pebbles flavored milk without having to let it soak too long and had a prominent flavor you can taste in the cake.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.