Pour the contents of both packets of gelatin into a bowl. Stir. Divide the mixture into three equal portions. Each portion will be about 1/4 cup minus a tablespoonful.
Divide the milk-cream mixture into three portions as well.
In a small pan, mix together one portion of gelatin, the coffee and one portion of the milk-cream mixture. Cook over medium heat, stirring, until the gelatin and coffee are completely dissolved without allowing the mixture to boil.
Pour the coffee panna cotta into one-cup molds. Allow to set, about five minutes.
Next, take another portion of gelatin and, in a pan, mix it with a second portion of the milk-cream mixture. Add the chocolate which I recommend that you chop or cut into small pieces. Cook over medium heat, stirring, until the chocolate is melted and the gelatin is dissolved. Do not allow the mixture to boil.
Pour the chocolate panna cotta on top of the coffee panna cotta and allow to set for another five minutes.
Finally, cook the last remaining portion of gelatin in the last portion of the milk-cream mixture, stirring until the gelatin is dissolved, and without allowing the mixture to boil. Pour over the chocolate panna cotta and allow to set. I recommend chilling.
To serve, you can top the chocolate and coffee panna cotta with whipped cream or a scoop of ice cream. Or, drizzle caramel syrup over the panna cotta, sprinkle with grated or shaved chocolate and enjoy.