Foolproof Holiday Fudge

http://www.marthastewart.com/350084/foolproof-holiday-fudge

Traditional fudge recipes require a candy thermometer and a fair amount of precision to get the texture just right; this streamlined recipe is simple enough for children to make (with supervision, of course) and relies on the addition of mini marshmallows for silkiness.
Martha Stewart Living, Special Issue 2008

Yield Makes 24 two-inch pieces
Ingredients

Vegetable oil, cooking spray
2 cups sugar
1 teaspoon salt
6 tablespoons unsalted butter
1 cup heavy cream
3 1/2 cups mini marshmallows
3 cups semisweet or white chocolate chips
1 teaspoon pure vanilla extract
1/2 cup crushed peppermint candy

Directions

Line a 9-by-13-inch baking pan with two sheets of waxed or parchment paper in a crisscross manner (one lengthwise, one crosswise) so ends overhang sides of pan; coat evenly with cooking spray.
In a heavy-bottomed saucepan over medium heat, cook sugar, salt, butter, cream, and marshmallows, stirring, until butter and marshmallows are almost melted, 5 to 6 minutes.
Bring mixture to a boil; cook, stirring occasionally, 5 minutes. Remove from heat. Add chips and vanilla; stir until chips are melted. Pour mixture into lined pan.
Let fudge cool in the pan at room temperature, 3 hours. Use edges of paper to lift out fudge; place on cutting board, and remove paper. Cut out shapes with cookie cutters, or cut fudge into bars. Sprinkle evenly with crushed candy.