Make the mozzarella skulls. Preheat the oven to 350ºF and set the silicon molds onto a rimmed baking sheet for stability. Lightly grease the interiors of the skull molds. Add a ball of mozzarella to each skull cavity. Bake for 6-8 minutes to soften the cheese - it will not melt but will become pliable. Use a folded paper napkin to press the softened cheese into the molds (the paper towel will absorb the liquid that is released from the mozzarella, which will be more than you think). Press the cheese well into the molds to get a good form, being careful not to burn yourself. Transfer the molds to the refrigerator and let chill for 8-10 minutes, then remove from the mold and repeat with remaining cheese until all the mozzarella is formed into skulls.

Slice the cherry tomatoes in half and then toss the tomatoes and mozzarella skulls, with the balsamic and olive oil. Scatter basil leaves over top and sprinkle with salt before serving.