Mix flour and sugar in a large bowl and add the butter cubes, crumbling with your fingertips to make breadcrumbs.
Beat the egg yolks and add it to flour mixture, mixing until the dough starts to form a ball.
Add a little ice water if too stiff.
Bring together on a floured surface and cover with cling film.
Refrigerate for at least an hour. When ready to make the hertzoggies, pre-heat the oven at 180°C.
On a floured surface, roll out the dough and cut circles with a cookie cutter to fit into the muffin tin cavities.
Put 1 teaspoon jam in the flour.
Beat egg whites until stiff.
Add the caster sugar while beating.
Fold in the coconut. Place a generous spoonful of meringue mixture on top.
Bake for 10 minutes, or until golden brown. Cool and store in an airtight container.