Chocolate-Marshmallow Fudge

INGREDIENTS

• 4 Tbs.(1/2 stick) unsalted butter, melted
• 1 cup firmly packed light brown sugar
• 1 cup granulated sugar
• 1/4 cup light corn syrup
• 1/2 cup half-and-half
• 1/8 tsp. salt
• 4 oz. bittersweet or semisweet chocolate, coarsely chopped
• 1/2 cup chopped walnuts
• 1 1/2 cups miniature marshmallows