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–+ servings
pink bento cake in a take away box
Ella Cooks

Microwave Bento Cake (No Cake Tin Needed!)

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While most bento cakes require baking and special pans, this microwave version makes the trend more accessible than ever! No oven, no cake tins, just a quick and easy method to create your own beautifully frosted, single-serving cake in under 30 minutes. Whether you’re celebrating something small or just treating yourself, this recipe delivers all the bento cake charm with none of the fuss.
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Prep Time 10 minutes
Cook Time 2 minutes
Decorating Time 15 minutes
Servings: 1
Course: Dessert
Calories: 550
Ingredients Method Nutrition Notes

Ingredients
  

Ingredients
For the Sponge Cake
  • 6 tbsp all-purpose flour
  • 3 tbsp granulated sugar
  • ½ tsp baking powder
  • Pinch of salt
  • 4 tbsp milk dairy or plant-based
  • 1 tbsp melted butter or neutral oil
  • ½ tsp vanilla extract
  • Vegan? Use plant-based milk and oil.
For the Frosting (Bento Cake Buttercream)
  • ¼ cup 60g unsalted butter (or vegan butter), softened
  • ½ cup 60g powdered sugar
  • ½ tsp milk or cream
  • ¼ tsp vanilla extract
Optional: food coloring, sprinkles, piping bag or ziplock bag

Method
 

Method
    Step 1: Mix the Cake Batter
    1. In a small bowl, mix flour, sugar, salt, and baking powder.
    2. Add milk, melted butter or oil, and vanilla. Stir until smooth and lump-free.
    3. Pour into your greased microwave-safe container, leaving some room at the top (it will rise!).
    Step 2: Microwave the Cake
    1. Microwave on high power for 2 minutes.
    2. Check: insert a toothpick in the center. If it comes out wet, microwave in 10–15 second bursts until just cooked (usually 2.5 to 3 minutes total).
    3. Let cool in the container for 5 minutes, then turn out onto a plate and cool completely.
    4. Don’t overheat, microwave cakes can dry out quickly. Stop cooking as soon as it’s set and springy to touch.
    Step 3: Level & Layer
    1. Slice off the domed top with a serrated knife to make it flat.
    2. If your cake is tall enough, slice it in half horizontally to create two layers.
    3. Optional: Trim the edges with a round glass or cutter to make a clean bento-style round cake (about 4 inches wide).
    Step 4: Make the Frosting
    1. Beat the softened butter until smooth.
    2. Gradually mix in powdered sugar and beat until fluffy.
    3. Add milk and vanilla, adjusting for consistency.
    4. Tint with a drop of food coloring for pastel tones (optional).
    Step 5: Decorate Bento-Style!
    1. Apply a thin crumb coat, chill for 5 minutes.
    2. Smooth a second layer of buttercream over the top and sides.
    3. Pipe a border around the top using a ziplock or piping bag.
    4. Add sprinkles or write a tiny message like:
    5. “Happy Mini Cake Day”
    6. “You Got This”
    7. “Sweetest Moment”

    Nutrition

    Calories: 550kcalCarbohydrates: 60gProtein: 5gFat: 30gSodium: 180mgSugar: 35g

    Notes

    Serving & Storage
    Store in the fridge for up to 2 days, covered.
    Let come to room temperature before serving for the best texture.
    Perfect for personal treats, birthdays, or gifting.

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