Combine sugar and 2 cups water in a saucepan and bring to a simmer over medium-high heat. Cook for 2 minutes, then add raspberries and rosewater and simmer for another 5 minutes, then remove from heat and stand for 15 minutes. Process mixture in a food processor or blender, then pour into a fine sieve double-lined with muslin, placed over a jug. Allow mixture to strain, without pressing on it, for 5 hours or until you have 600ml of liquid.
Place ½ cup of strained raspberry liquid in a saucepan and bring to a simmer over high heat. Squeeze excess water from gelatine, add gelatine to pan and stir to dissolve. Return gelatine mixture to remaining raspberry liquid, stir to combine and pour into six 100ml-capacity moulds and refrigerate for 4 hours or until set.
Dip moulds into warm water for a few seconds, then invert onto plates, drizzle with cream and serve immediately.