Place the water in a large mixing bowl and sprinkle the gelatin on top. Stir briefly, then let stand for 5 to 10 minutes.
While the gelatin softens, heat the eggnog, vanilla extract, rum extract, cinnamon and nutmeg in a saucepan over medium heat until warm but not scalded.
Slowly whisk the warm eggnog into the gelatin mixture until the gelatin is completely dissolved. Set aside to cool to room temperature.
Once the eggnog mixture has cooled, transfer it into 6 (or 8) individual serving dishes. Cover with plastic wrap and refrigerate until firm, at least 4 hours.
While the panna cotta sets, prepare the Caramel-Rum Sauce.
Place the sugar and water into a 1 quart saucepan over medium-high heat (375°F). Bring the mixture to a boil, whisking until the sugar has dissolved. It's important that you don't leave the sugar unattended as it can burn very easily.
Continue cooking the sugar, stirring occasionally, until it turns from deep gold to light brown, then immediately remove the pan from the heat. Quickly add the butter, whisk until melted, then slowly whisk in the cream and rum until smooth.
Transfer the warm caramel to a glass jar. Cover and refrigerate until an hour before serving. Makes about 3/4 cup.
To finish the panna cotta, spoon 2 to 3 teaspoons of the Caramel-Rum sauce over the top of each serving.
6 to 8 servings
Tips for Making This Recipe
If you don't have any rum extract, just replace it with additional vanilla.