Whisk together cocoa powder, cinnamon, cornstarch, and sugar in a cold saucepan.
Whisk in milk and heavy cream.
Bring to a simmer over medium low heat, stirring constantly, until mixture thickens.
Add chopped dark chocolate and stir.
Remove from heat and stir in vanilla.
Pour into individual ramekins or dessert containers and cover surface with plastic wrap.
Refrigerate for at least 2-4 hours.
When ready to serve, whip heavy cream, confectioner sugar, and vanilla until soft peaks form.
Remove plastic from pudding and top with whipped cream and raspberries.