You can make your own hot chocolate mix really easily and then combine it with warm milk. To make the mix, stir together equal proportions of cocoa powder and sugar (like 1/2 C of each). Then whenever you want hot chocolate, warm some milk and add 1 or 2 tablespoons to each mug.
If you want cinnamon hot chocolate, you can add the cinnamon flavor to the milk before stirring in the cocoa mix. To do that, put the amount of milk you want in a small pan. Add 1 cinnamon stick (broken) for each cup of milk. Heat over very low heat for about 10 minutes. Do not let the milk scald. Turn off the heat and let the milk sit for an hour while the cinnamon flavor is released from the sticks. Finally, reheat, pour the milk into mugs, and stir in the cocoa mix that you made.