Step 1

Prep baking pan and assemble ingredients: Prepare everything in advance and have ready to go — chopped chocolate, chopped nuts, the marshmallow cream already out of the jar and in a bowl that you can easily scrape out with a rubber spatula.Line a 9x13 baking pan with foil, butter the inside.

Step 2

Boil sugar, butter, and milk for 4 minutes: In a 3-quart, thick-bottomed saucepan, bring sugar, butter, and milk to a rolling boil on medium heat, stirring constantly once the mixture begins to bubble.Once the mixture reaches a boil, set your timer to 4 minutes. You will want to remove the mixture from the heat once it reaches 234°F on a candy thermometer (adjust for altitude as needed) which should take about 4 minutes. If you don't have a candy thermometer, just go with the four minutes.

Step 3

Finish the fudge: Remove from heat. Quickly stir in chocolate and marshmallow creme.Once the chocolate and marshmallow creme have melted and are well mixed, stir in the vanilla and then the walnuts.

Step 4

Pour into prepared pan.

Step 5

Cool to room temperature before slicing (about 4 hours). You may want to chill in the refrigerator to get it more firm.