Prepare the Liquid Mixture: In a large measuring cup, combine 1 cup of eggnog and 1 cup of heavy whipping cream.

Mix the Dry Ingredients: In a medium saucepan, whisk together ½ cup of granulated sugar, ¼ cup of cornstarch, a pinch of salt, and ½ teaspoon of ground nutmeg.

Incorporate the Egg Yolks: Add 4 large egg yolks to the dry mixture, whisking until smooth.

Combine with the Eggnog Mixture: Gradually add the prepared eggnog mixture to the saucepan, whisking continuously.

Cook the Mixture: Place the saucepan over medium heat and cook, stirring constantly for about 8-10 minutes until thickened.

Add Flavor and Texture: Remove from heat and mix in 1 teaspoon of rum extract and 2 tablespoons of unsalted butter until melted.

Strain and Cool: Pour the pudding through a fine-mesh sieve into a clean bowl and cover with plastic wrap directly against the surface.

Chill the Pudding: Refrigerate for at least 4 hours or preferably overnight.

Serve and Garnish: Spoon into serving dishes and top with whipped cream, grated nutmeg, and sugared cranberries.