Even if you’ve never made candy before in your life, give this fudge a try. True to its name (and thanks to the presence of marshmallows), it won’t seize or crumble or make you tear your hair out. Perfect for Christmastime.
Grease or line an 8x8-inch pan with nonstick foil. Set aside.
In a 2-quart saucepan over medium heat, combine the sugar, milk, marshmallows, butter, and salt. Cook, stirring constantly, until the mixture is bubbling.
Boil and stir for 5 minutes; remove from the heat. Stir in the chocolate chips until completely melted. Add the walnuts and vanilla.
Spread into the prepared pan and cool for 4 to 6 hours in the refrigerator before cutting.
Store in an airtight container in the refrigerator or at room temperature.