Step 1

Preheat oven to 180C. Grease and line the base and sides of a 20cm square cake pan with baking paper. Use an electric mixer to beat the butter and sugar in a bowl until pale and creamy. Add the eggs, 1 at a time, beating well after each addition. Add the sour cream and stir to combine. Add the flour, coconut, lemon rind and lemon juice and stir to combine. Add the lemon curd and gently fold until just marbled through.

Step 2

Spoon into the prepared pan and smooth the surface. Bake for 45-50 mins or until a skewer inserted in the centre comes out clean. Cool in the pan for 5 mins before turning onto a wire rack to cool completely.

Step 3

To make the lemon icing, combine the icing sugar, lemon curd, butter, lemon juice and water in a heatproof bowl over a saucepan of simmering water. Stir until smooth and runny.

Step 4

Place the coconut in a large bowl. Use a large serrated knife to cut the cake into 4 squares, then cut each square diagonally into 4 triangles. Using 2 forks, dip 1 cake triangle into the icing and gently turn to coat. Lift and let the excess icing drip off. Transfer to the coconut and gently turn to coat. Transfer to a plate. Repeat with the remaining cake, icing and coconut. Set aside for 30 mins to set.