Campfire Skillet Cookie

Name: Campfire Skillet Cookie
Ingredients: 2 sticks (1 cup) unsalted butter, at room temperature; 2 1/2 cups all-purpose flour (see Cook's Note); 1/2 teaspoon baking powder; 1/2 teaspoon fine salt; 1 1/2 cups sugar; 1 teaspoon pure vanilla extract; 1 large egg; 7 red hard candies, such as Jolly Rancher, crushed; 7 pink hard candies, such as Jolly Rancher, crushed; One 16-ounce can vanilla frosting; 3 drops leaf green gel food coloring; 14 chocolate wafer sandwich cookies (1 sleeve), crushed; 3 pirouettes cookies, cut into thirds; 6 milk chocolate-covered caramel and biscuit candy bars, such as Twix (three 1.79-ounce packages); 6 marshmallows; 6 pretzel rods