This 1 Minute Microwave Rainbow Mug Cake is a burst of joy in every bite, combining vibrant colors with a soft, fluffy texture. Perfect for when you need a quick treat, it’s ready in just six minutes—five to prep and one to cook. The moist cake melts in your mouth, while the rainbow layers add a playful surprise that’s as delightful to look at as it is to eat.
With its rich vanilla flavor and tender crumb, this mug cake feels like a mini celebration in a cup. It’s ideal for satisfying sudden sweet cravings or brightening up a busy day. The convenience of microwave baking means you can enjoy a homemade dessert without the fuss, making it a go-to for both kids and adults alike.
Ingredients for 1 Minute Microwave Rainbow Mug Cake
- ½ cup (100g) sugar
- 1 stick (100g) butter, softened at room temperature
- 2 eggs, at room temperature, lightly beaten
- 1 teaspoon vanilla extract
- 1 cup (110g/4oz) all-purpose flour
- ½ teaspoon baking powder
- ¼ teaspoon baking soda
- Pinch of salt
- Food colouring (red, orange, yellow, green, blue)
Step-by-Step Instructions
- In a large bowl, cream the sugar and butter together until light in color and fluffy in texture (about 3 minutes). Use a hand whisk.
- Crack in one egg, mix well, and repeat with the second egg. Then, pour in the vanilla extract and beat for another minute until well combined.
- Add the dry ingredients (flour, baking powder, baking soda, and salt) and mix until just combined. Do not over-mix!
- Divide the mixture evenly between 5 small bowls.
- Add a couple of drops of food colouring to each bowl (one color per bowl) and mix gently. Avoid over-mixing to maintain vibrant colors.
- Spoon the colored batter into 4 microwave-safe mugs, layering one spoonful at a time to create a marbled effect.
- Microwave each mug for 45 seconds. (Note: Microwave times may vary, so check for doneness. The cake should be moist but not overcooked.)
- Let cool slightly, then decorate with cream cheese frosting or your favorite toppings. Enjoy!
Creative Toppings to Elevate Your Mug Cake
While the cream cheese frosting is a classic choice, try drizzling your rainbow mug cake with chocolate ganache or a caramel sauce for extra indulgence. For a fruity twist, top with fresh berries or a dollop of whipped cream. Sprinkle with colorful sprinkles or edible glitter to match the rainbow theme!
Quick Storage and Reheating Tips
If you have leftovers (unlikely!), store your mug cake in an airtight container at room temperature for up to 1 day. To reheat, microwave for 10-15 seconds to restore its soft, fluffy texture. Avoid overcooking during reheating to keep it moist.
Fun Variations to Mix It Up
Swap the food coloring for natural alternatives like beet juice (red), turmeric (yellow), or spinach juice (green). For a chocolate version, add 2 tablespoons of cocoa powder to the dry ingredients. Feeling adventurous? Fold in mini chocolate chips or rainbow sprinkles for added texture.
Microwave Power Tips for Perfect Results
Microwaves vary, so start with 45 seconds and check the cake’s doneness. If it’s still gooey, add 10-second increments until just set. Remember, the cake will continue to cook slightly after microwaving, so slightly undercooked is better than overdone!
Why Room Temperature Ingredients Matter
Using room temperature butter and eggs ensures a smoother batter and even baking. If you’re short on time, soften butter in the microwave for 5-10 seconds and place eggs in warm water for a few minutes to bring them to room temperature quickly.
1 Minute Microwave Rainbow Mug Cake
Ingredients
- ½ cup sugar 100g
- 1 sticks butter 100g, softened at room temperature
- 2 eggs at room temperature, lightly beaten
- 1 teaspoons vanilla extract
- 1 cups All purpose flour 110g/ 4oz
- ½ teaspoon baking powder
- ¼ teaspoon baking soda
- pinch salt
- red, orange, yellow, green, blue, food colouring
Instructions
- In a large bowl cream the sugar and butter together until light in colour and fluffy in texture – about 3 minutes. Use a hand whisk.
- Crack in an egg, mix in well, and follow with the next egg. Then pour in the vanilla extract. Beat for another minute until well combined.
- Add in the dry ingredients until just combined – don’t over-mix!
- Divide the mixture as evenly as you can between 5 bowls.
- Add a couple of drops of food colouring to each bowl and mix very gently – again, do not over-mix!
- Spoon the colors between the 4 mugs one spoonful at a time. Lay the different colored cake batter on top to create a marbled effect.
- Microwave for 45 seconds (every microwave is different so cooking may vary).
- Take care not to overcook the cake or it will dry out fast.
- Decorate your cake with my cream cheese frosting
