Combine the cheese, cocoa powder, sugar, and salt. Mix the ingredients using a mixer with a flat beater attachment. Add the eggs in two or three stages, mixing after each addition. Heat the cream and then mix it with the chocolate. Pour this mixture into the cheese mixture and blend until smooth. Transfer the batter into wooden rings with a diameter of 12 cm lined with baking paper, about 400 g per ring. Bake at 240-250°C (464-482°F) with the fan set to 3 for 15–17 minutes. After cooling, decorate the cheesecakes with Terra vita hazelnut spread.