M&M Surprise Cupcakes with Rainbow Frosting

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M&M Surprise Cupcakes with Rainbow Frosting

Yield Makes 12 cupcakes 1x
Prep: 40 minutesCook: 20 minutesTotal: 1 hour

Chocolate cupcakes filled with M&M’s and topped with creamy frosting,



  • 105 grams (3/4 cup) plain flour
  • 40 grams (1/2 cup) cocoa powder
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon baking powder
  • 100 grams (1/2 cup) caster sugar
  • 45 grams (1/4 cup) brown sugar
  • 2 large eggs
  • 115 grams (1/2 cup or 1 stick) unsalted butter, softened
  • 1 teaspoon vanilla extract
  • 120 ml (1/2 cup) buttermilk
  • 1 cup mini M&M’s


  • 115 grams (1/2 cup or 1 stick) unsalted butter, softened
  • 500 grams (4 cups) icing or powdered sugar
  • 23 tablespoons milk
  • A few drops of food colouring


  1. Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced. Line a 12 hole muffin tin with patty cases.
  2. In a large mixing bowl, sift the flour, cocoa powder, baking soda, baking powder and then add the sugars. Pop the butter into the microwave for a short burst, 10 seconds or so at a time, until it becomes very soft but just before it is completely melted. Give it a stir with a fork to eliminate any lumps.  In a separate mixing bowl, add the eggs, vanilla and butter and whisk together until smooth. Then add the wet mixture into the dry mixture, along with the buttermilk and gently fold until just combined.
  3. Spoon the mixture into the prepared patty cases and pop into the oven. Bake for 18-20 minutes or until just cooked through. Set cakes out onto a wire rack and leave to cool completely. Carefully cut out a hole in the middle of each cake and fill with mini M&M’s.
  4. To make the icing, add the butter to a large mixing bowl, beat with an electric mixture until soft and creamy.  Gently sift in one cup of the icing sugar and continue to beat. Add a tablespoon or two of milk to help loosen up the mixture. Add the rest of the icing sugar, one cup at a time. Continue to add a tablespoon of milk as needed – but be careful, you don’t want the frosting too runny. It should be nice and creamy but thick enough to hold its shape when piped. Divide the icing into three bowls.
  5. In each bowl, add a few drops of food colouring and stir thoroughly until the icing is dyed to the colours you want. Grab your disposable piping bag and insert a large star tip into the end. Very gently add spoonfuls of one colour of icing and try keep it to one side of the piping bag. You don’t have to be exact, so do the best you can. Then gently spoon the second coloured icing on top and then the third colour on top of that. Gently press down to remove any air bubbles and force the icing down to the tip. Twist the top of the bag and then pipe the icing onto the cupcakes. The first one probably won’t have all three colours so use that one as a test run.


If you’re visual person, check out this video by Cupcake Jemma which shows how to pipe Rainbow Buttercream.

For tips on piping check out my cupcake frosting post HERE.

Author: Jessica HolmesCategory: DessertCuisine: American
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