Simple Chocolate Fudge

Makes 36 squares.

• 4 tablespoons (1/2 stick) unsalted butter, plus more for pan
• 3 cups mini marshmallows
• 1 cup sugar
• 1/2 cup heavy cream
• 1/2 teaspoon salt
• 1/2 teaspoon pure vanilla extract
• 1 bag (12 ounces) semisweet chocolate chips
• 1 cup walnuts, coarsely chopped
  

1. Butter an 8-inch square baking pan; line with 2 crisscrossed pieces of parchment paper, leaving an overhang. Butter paper.
2. In a large saucepan, combine butter, marshmallows, sugar, cream, and salt; cook over medium, stirring occasionally, until marshmallows are melted, 8 to 10 minutes. Off heat, stir in vanilla, chocolate chips, and 1/2 cup walnuts until chocolate is melted.
3. Pour fudge into prepared pan, and smooth top; sprinkle with remaining walnuts. Let cool 30 minutes. Refrigerate until set, about 1 hour.
4. Using overhang, lift fudge onto a cutting board; cut into squares (6 rows by 6 rows).