Line a 13x9x2-inch pan will foil, extending foil over the edges of the pan. Butter foil. Set aside. (I skip the foil & just butter the pan)

Place the chocolate chips, cut-up chocolate bar, marshmallow creme, and nuts in a bowl. Set aside.

Butter sides of a heavy 3-quart saucepan.

In the saucepan, combine sugar, evaporated milk, butter, and instant espresso (if you choose to use it). Cook and stir over medium-high heat until mixture boils. Reduce heat to medium; continue cooking & stirring for ten minutes.

Remove pan from heat. Add the bowl of chocolate chips, cut-up chocolate bar, marshmallow creme, nuts, as well as the vanilla; stir until the chocolate melts and the mixture is combined. Beat by hand for one minute (you may want another person to help with this). Spread in the prepared pan. Score into 1-inch squares while warm. When fudge is firm, cut fudge into squares. Store in a tightly covered container in the refrigerator (we prefer it kept out at room temperature). Makes about 4 pounds.