Method

Step 1: Mix the Cake Batter

• In a small bowl, mix flour, sugar, salt, and baking powder.
• Add milk, melted butter or oil, and vanilla. Stir until smooth and lump-free.
• Pour into your greased microwave-safe container, leaving some room at the top (it will rise!).
  

Step 2: Microwave the Cake

• Microwave on high power for 2 minutes.
• 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).
• Let cool in the container for 5 minutes, then turn out onto a plate and cool completely.
• 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

• Slice off the domed top with a serrated knife to make it flat.
• If your cake is tall enough, slice it in half horizontally to create two layers.
• 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

• Beat the softened butter until smooth.
• Gradually mix in powdered sugar and beat until fluffy.
• Add milk and vanilla, adjusting for consistency.
• Tint with a drop of food coloring for pastel tones (optional).

Step 5: Decorate Bento-Style!

• Apply a thin crumb coat, chill for 5 minutes.
• Smooth a second layer of buttercream over the top and sides.
• Pipe a border around the top using a ziplock or piping bag.
• Add sprinkles or write a tiny message like:
• “Happy Mini Cake Day”
• “You Got This”
  
• “Sweetest Moment”