Preheat the oven to 170C and line your baking tin. I used a 9 by 9 square baking tin.

Cream together the butter, oil and sugar until almost white and light and fluffy. This should take between 3-5 minutes, whisking on a medium setting. Scrape down the sides as you go.

Pour in the eggs and vanilla extract and whisk until combined.

Add the flour, salt and baking powder. Start to combine with a whisk on a low setting.

Just as it's starting to come together, pour in the milk. Continue to combine by whisking gently. We don't want to do this for too long, about 1 - 2 mins max.

Scrape down the sides of the bowl all the way to the bottom and give the mixture a final folding to ensure the batter is well combined.

Pour the batter into the tin and spread it around evenly, making sure to get into the corners.

Tap a few times on a flat surface to release any extra air bubbles.

Bake uncovered for 35 mins. Then quickly place a piece of foil on top and bake for another 15 mins. (This has to be done quickly so the heat doesnt escape from the oven ans cause the cake to collapse. This is if you don't want the top to brown too much. You can skip this step if you wish.)

Take the cake out of the oven and carefully take off the foil, so it doesn't take off any of the cake with it as you go.

A toothpick should come out clean.

Leave to cool in the tin for 10 mins.

Remove the cake from the tin and leave to cool completely.

Generously spread on the jam and sprinkle generously with dessicated coconut.

Serve with lashings of custard.