Preheat oven to 180 degrees celsius.
Grease and line a rectangular slice tray (18cm X 28cm) with baking paper.
Place the plain flour, 1/2 cup of caster sugar and the chilled butter into a food processor and process until the mixture resembles breadcrumbs.
Add 1 egg and the vanilla essence.
Process until the mixture has formed into a dough.
Press dough firmly into the base of the prepared pan.
Bake for 15 to 20 minutes, or until golden.
Spread jam over warm base.
Whisk the remaining eggs and 1/2 cup caster sugar together.
Stir through the coconut and spread over the jam.
Bake for 25 minutes, or until golden.
Allow to cool completely in the pan before cutting into slices.