- Lightly oil a 2-litre (8-cup) aspic mould.
- In a bowl, sprinkle the gelatin on the water. Let soften for 5 minutes.
- In a saucepan off the heat, whisk together the milk, maple syrup, egg yolks and cornstarch. Bring to a boil over medium heat, whisking constantly, and cook until smooth and thick, about 1 minute.
- Remove from the heat, add the gelatin and whisk until completely dissolved. Stir in the maple extract. Pour into a bowl and let cool. Cover and refrigerate until the mixture reaches room temperature and is very thick but not set, about 1 1/2 hours.
- Using a whisk, gently stir in the whipped cream until the mixture is smooth. Pour into the mould. Cover and refrigerate for about 8 hours.
- Unmould onto a serving plate.