Pour 3 cups of almond milk into a saucepan, keeping back 6¾ tablespoons in a small bowl. Whisk ½ cup of cornstarch into the milk in the bowl until smooth.
Add ½ cup of sugar, 3 drops of rose water, and 6 tablespoons of water to the saucepan. Warm over low heat, whisking, until the sugar dissolves.
Whisk in the cornstarch mixture and bring to a boil, stirring, until the pudding is thick enough to coat a spoon. Pour into dessert cups and refrigerate for at least 2 hours.
For the syrup, bring ⅔ cup of water, ¾ cup of sugar, and ¾ cup of dried hibiscus flowers to a boil in a small pan, stirring. Lower the heat and simmer for 5 minutes.
Chill the syrup, strain it through a sieve, and spoon it over the puddings.
