Slow-cooker chai hot chocolate

Name: Slow-cooker chai hot chocolate
Prep time: 5 min
Cook time: 1 h
Total time: 1 h 5 min
Cuisine: Asian, Indian
Ingredients: 1 cinnamon stick or quill; 2 whole star anise; 4 whole cloves; 2.50 gm ground ginger; 1 tsp ground cardamom; 1/2 tsp freshly ground fennel seeds; 1/2 tsp ground allspice; Freshly ground black pepper; 2l milk; 400g dark chocolate, finely chopped; Whipped cream, to serve; Ground cinnamon, to serve