Ingredients

Step by step

1. Preheat the oven to 180°C, fan 160°C, gas 4. Butter a 30cm x 20cm traybake tin and line the base and sides with baking paper.
2. In a large bowl, cream together the softened butter, sugar and lemon zest with an electric mixer, until light and fluffy. Beat in the eggs, one at a time, adding a spoonful of the flour with each one. Fold through the remaining flour, along with the baking powder and salt. Once combined, stir through the milk to loosen. Transfer the batter to the prepared tin and level out. Bake for 30-35 minutes until risen, golden brown and a skewer inserted comes out clean. Leave to cool in the tin for 10-15 minutes.
3. While the sponge is baking, make the syrup: pour the lemonade and lemon juice into a saucepan and add the sugar. Bring to a simmer, then bubble for 10-12 minutes until reduced by about half. Set aside to cool.
4. Prick the warm cake all over with a skewer. Evenly pour over the lemonade syrup and leave the cake to soak and cool completely in the tin.
5. To decorate, grind the freeze-dried strawberries to a powder using a pestle and mortar (or use a powerful mini food processor). Beat the butter with a pinch of salt using an electric mixer until very soft and creamy. Beat in the icing sugar, in two batches, adding the powdered strawberries with the second batch. Add the milk and beat until combined. For a stronger colour, add enough food colouring to reach your desired shade of pink.
6. Remove the sponge from the tin onto a serving board. Spoon the buttercream icing onto the cake and use a palette knife to swirl and spread it to the edges. Decorate with the vermicelli sprinkles and cut into squares to serve. Leftover cake will keep for up to 4 days in an airtight container in a cool place.