Preheat the oven to moderate, 180°C (350°F). Line 2 oven trays with baking paper.

In a large bowl, beat together the softened butter and caster sugar until pale and creamy. Add the egg and vanilla essence, beating until well combined.

Using a large metal spoon, gently fold the sifted flour and coconut into the mixture until a dough forms.

Roll tablespoons of the dough into balls. Roll each ball in the extra desiccated coconut to coat it. Place the coated balls onto the prepared trays, leaving about 6cm of space between each one. Flatten each ball slightly.

Bake the biscuits in two batches, for 15-20 minutes each, or until they turn lightly golden brown.

While the biscuits are still hot, use a teaspoon to make indents in the center of each one.

Allow the biscuits to cool on the trays for 5 minutes before transferring them to wire racks to cool completely.

Once the biscuits are completely cooled, fill the indents in each one with a small amount of jam.