Ingredients:

  • 225g unsalted butter, softened
  • 225g caster sugar
  • 4 large eggs
  • 225g self-raising flour
  • 1 tsp baking powder (if using all-purpose flour)
  • Pinch of salt
  • Zest of 1 lemon
  • Zest of 1 orange
  • 2 tbsp milk
  • 250g unsalted butter, softened
  • 500g icing sugar, sifted
  • 2-3 tbsp milk or cream
  • 1 tsp vanilla extract
  • 150g fresh or frozen raspberries, pureed

Instructions:

  1. Preheat oven to 180°C (350°F, Gas Mark 4). Grease and flour two 8-inch cake pans.
  2. Cream together the softened butter and sugar until light and fluffy.
  3. Beat in the eggs one at a time, ensuring each is fully incorporated.
  4. Stir in the lemon and orange zest. Gradually add the flour (and baking powder, if using all-purpose), and salt, alternating with the milk. Mix until just combined.
  5. Divide the batter evenly between the prepared cake pans. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
  6. Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.
  7. Puree the raspberries using a blender or food processor. Strain the puree through a fine-mesh sieve to remove seeds if desired.
  8. Beat the softened butter until light and fluffy. Gradually add the sifted icing sugar, alternating with the milk or cream, until a smooth and creamy buttercream forms. Stir in the vanilla extract.
  9. Divide the buttercream in half. Gently fold the raspberry puree into one half of the buttercream.
  10. Place one cake layer on a serving plate. Spread with half of the plain buttercream, then half of the raspberry buttercream. Top with the second cake layer.
  11. Frost the top and sides of the cake with the remaining buttercream, alternating the plain and raspberry flavors to create a swirl effect.
  12. Refrigerate the cake for 30 minutes to help the buttercream set.