Heat the Panna Cotta until it is completely liquid.
Set aside 50 ml and pour into skull-shaped silicone moulds.
Place in the refrigerator.
Set aside another 50 ml of Panna Cotta and dissolve a small amount of active charcoal in it, so that the Panna Cotta turns pitch-black.
Pour the black Panna Cotta into spherical silicone moulds.
Place in the refrigerator to set.
Then pour the rest of the (white) Panna Cotta on top and place the whole thing into the refrigerator.
Then place in the freezer so that it hardens completely.
Unmould the Panna Cotta ‘cow’s eyes’ and keep them tightly sealed in the freezer.