01 - Line an 8x8-inch baking pan with parchment paper, creating an overhang for easy removal.
02 - In a medium saucepan over medium heat, blend unsalted butter, eggnog, and granulated sugar. Stir regularly until the mixture reaches a gentle boil.
03 - Reduce to low heat and simmer for 4 to 5 minutes, stirring constantly to prevent scorching.
04 - Remove pan from heat. Add white chocolate chips, ground nutmeg, ground cinnamon, and vanilla extract. Stir thoroughly until the chocolate melts and the mixture becomes smooth.
05 - Quickly transfer the fudge mixture to the prepared pan, spreading evenly with a spatula. Sprinkle freshly grated nutmeg evenly on top, if desired.
06 - Let cool at room temperature for 30 minutes. Refrigerate for a minimum of 2 hours or until firm.
07 - Lift fudge from the pan using the parchment paper overhang. Cut into 36 even squares using a sharp knife.