1 tablespoon plus 3/4 cup butter, softened, divided
3 cups sugar
2/3 cup eggnog
2 tablespoons heavy whipping cream
1 package (10 to 12 ounces) white baking chips
1 cup marshmallow creme
1 cup finely chopped walnuts
2 teaspoons vanilla extract
Line a 13-in. x 9-in. pan with foil and grease the foil with 1 tablespoon butter; set aside. In a large saucepan, combine the sugar, eggnog, cream and remaining butter. Bring to a boil over medium heat, stirring constantly. Reduce heat; cook until a candy thermometer reads 238° (soft-ball stage), stirring occasionally.
Remove from the heat. Stir in chips until melted. Stir in the marshmallow creme, walnuts and vanilla.
Spread into prepared pan. Cool to room temperature. Using foil, lift fudge out of pan. Discard foil; cut fudge into 1-in. squares. Store in an airtight container in the refrigerator.
Editor's Note: This recipe was tested with commercially prepared eggnog. We recommend that you test your candy thermometer before each use by bringing water to a boil; the thermometer should read 212°. Adjust your recipe temperature up or down based on your test.