Heat the oven to 180C (160C fan)/350F/gas mark 4, and grease and line two 20 cm sandwich cake tins.

In a bowl, mix the flour, baking powder and salt.

Gently heat the milk and butter in a small saucepan until the butter melts, then take off the heat and stir in the oil and lemon zest.

In another large bowl, whisk the eggs and sugar on high speed for five to seven minutes, until thick and creamy: when you lift the whisk, the eggs should leave a trail on the surface for a few seconds before sinking back in.

Using a spatula, fold in the flour mixture in two batches, until smooth.

Now add the milk mixture in three batches, folding well to combine.

Divide evenly between the two lined tins, then bake for 25-30 minutes, until browned and a skewer inserted into the middle comes out clean.

Leave to cool for 10 minutes, then remove from the tins, transfer to a rack (or two racks) and leave to cool completely.

Meanwhile, make the ganache.

Gently heat the cream in a saucepan and, once it's warm, stir in the curd until combined.

Take off the heat and stir in the chocolate, until it's melted.

Put the cooled cakes bottom-side up on a rack set over a baking tray.

Pour the ganache over the cakes, and use a palette knife to spread it evenly over the bottoms and sides.

Put aside to set for 10 minutes, then turn over and cover the tops and sides with desiccated coconut.

Leave for 20-30 minutes.

Make the filling by whipping the cream and vanilla to just before stiff peaks, then spoon into a piping bag fitted with a large round nozzle.

Put one cake coconut-side down on a serving plate.

Pipe large blobs of cream around the cake, then pipe the rest in the middle.

Smooth the middle with a palette knife and spread the curd on top.

Put the second cake on top, this time coconut-side up, then slice and serve.