Key lime pie cupcakes

A delightfully tart cupcake alternative with marshmallow frosting - and a limey surprise inside



  1. Preheat the oven to 180°C.
  2. Line a 12-hole muffin tin with cases.
  3. Cream together the butter and sugar until pale and smooth. Add the eggs one at a time, beating after each addition.
  4. Combine the flours in a separate bowl. Pour the milk into a jug and stir in the vanilla.
  5. Add a third of the flours to the creamed mixture and beat well. Pour in a third of the milk and vanilla and beat again. Repeat until all the flour and milk have been added. Spoon the mixture into the muffin cases. Bake for 20-25 minutes until golden.
  6. Cool in the tin for 10 minutes, then put on a wire rack to cool completely before icing.
  7. For the icing, place the sugar, syrup and water in a pan and cook on a high heat until the mixture reaches ‘soft-ball’ stage.
  8. In a separate bowl, whisk the egg whites until soft peaks start to form. Remove the sugar mixture from the heat.
  9. Using an electric hand mixer on a low speed, pour the hot sugar mixture in a slow, steady stream into the egg whites, beating all the time.
  10. Turn the mixer up to a medium-high speed and whip until the mixture becomes thick, glossy and cool. Add the vanilla extract.
  11. To assemble, scoop out about 2cm of sponge from the centre of each cupcake. Fill each hole with lime curd, top with the marshmallow icing and a sprinkle of lime zest.

Makes 12

What you need:

For the vanilla sponge:

  • 110g unsalted butter
  • 225g golden caster sugar
  • 2 large eggs
  • 150g self-raising flour
  • 125g plain flour
  • 120ml semi-skimmed milk
  • 1 tsp vanilla extract

For the marshmallow icing:

  • 120g granulated sugar
  • 80g golden syrup
  • 1½ tbsp water
  • 2 large egg whites
  • ½ tsp vanilla extract

To decorate:

  • Lime curd
  • Zest of 2 limes

From Primrose Bakery Everyday by Martha Swift (£20, Square Peg). 

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