Preheat broiler; set upper rack 4 inches from theflame. Scatter the marshmallows on a baking sheet,and broil until dark golden brown, 1 to 2 minutes.Advertisement
Process ice cream and milk in a blender until thick and creamy. Add all but 1/2 cup of the marshmallows; puree for 5 seconds, or until marshmallows are just combined but still holding some shape. Pour milkshakes into 6-ounce serving glasses; garnish with remaining toasted marshmallows. Serve immediately.