In a medium saucepan, whisk together the unsweetened cocoa powder, gelatin, and a pinch of salt until well combined.

Pour the cold milk into the saucepan with the dry ingredients and let it sit for 5 minutes to allow the gelatin to bloom.

Add the remaining 2 cups of milk and maple syrup to the saucepan, then heat over medium heat, whisking constantly until the mixture is hot and the gelatin is fully dissolved (do not boil).

Remove the saucepan from the heat and stir in the vanilla extract.

Carefully pour the chocolate mixture into individual ramekins or a large serving dish, then refrigerate for at least 4 hours, or until firmly set.