Line an 8 x 8-inch baking pan with aluminum foil. Set aside.
Combine the marshmallow cream, sugar, evaporated milk, butter and salt in a saucepan and bring to a boil over medium-high heat. Cook for 5 minutes, stirring constantly
Remove from the heat and add all of the chocolate chips (both kinds). Stir until the mixture is smooth.
Add the nuts and vanilla and stir to combine. Spread the fudge into the foil-lined pan. Refrigerate until firm, about 2 hours. Let stand at room temperature for 15 minutes before cutting into squares.