In a deep sauce pan add sugar and water. Bring to a boil stirring often. Reduce to low heat until it becomes clear and thick syrup, 10-15 minutes. Add blueberries. When it boils; remove from stove, add lemon juice, rosewater and vanilla. Bring to a third gentle boil, stir gently and remove from the stove.
Allow to cool before serving. Serve with ice cream.