1. Pour 1 cup whole milk into a small bowl and sprinkle 2 1/2 teaspoons unflavored gelatin powder over the top. Let sit 5 minutes to bloom.

2. In a medium saucepan, combine 2 cups heavy cream, 1 cup eggnog, and 1/2 cup granulated sugar. Heat gently, stirring, until sugar dissolves and mixture steams (do not boil).

3. Remove from heat. Stir in the bloomed gelatin until fully dissolved. Add 1 teaspoon vanilla extract and 1/4 teaspoon freshly grated nutmeg. Strain mixture through a fine mesh sieve into a large measuring cup.

4. Divide mixture evenly into 6 ramekins or glasses. Let cool 10–15 minutes, then refrigerate at least 4 hours until set.

5. For the cranberry sauce, combine 1 1/2 cups cranberries, 1/2 cup sugar, 1/4 cup orange juice, 2 tablespoons water, 1 tablespoon orange zest, and a pinch of salt in a saucepan. Simmer over medium heat, stirring often, until cranberries burst and sauce thickens, about 10–12 minutes.

6. Remove from heat. Stir in 1 tablespoon orange liqueur (if using). Cool to room temperature, then chill until serving.

7. To serve, unmold panna cotta by dipping ramekins briefly in warm water. Invert onto plates. Top generously with spiked cranberry sauce and garnish with extra orange zest or sugared cranberries if desired.