In a medium bowl, whisk together the ricotta cheese and milk until smooth. Add the simple syrup and vanilla essence. Stir to combine.
Pour the ricotta mixture into an ice cream maker and freeze according to the manufacturer's directions. Add the chocolate chips 10 minutes before the end of freezing.
Stand three sugar cones in each of the four glass tumblers. Mix the chocolate-hazelnut spread and chocolate chips together in a small bowl. Place the bowl over a pan of simmering water, making sure the bottom of the bowl does not touch the water. Stir until the chocolate chips have melted and the mixture is smooth.
Spoon 2 teaspoons of the chocolate mixture into each sugar cone. Place the glasses in the freezer for 10 to 15 minutes until the chocolate becomes firm.
Using a 60ml ice cream scoop, place one scoop of ice cream on top of each granulated sugar cone. Serve immediately.
Simple sugar syrup:
In a saucepan, combine the water and caster sugar over medium heat. Bring to a boil, reduce heat and simmer for 5 minutes, stirring occasionally, until the caster sugar has dissolved. Take the pan off the heat and allow the syrup to cool.