One 16-ounce package marshmallows
6 tablespoons unsalted butter, cut into pieces
1 teaspoon pure vanilla extract
Green gel food coloring, for tinting
6 cups cornflakes
Mini round cinnamon candies, for decorating
Red sour candy roll-ups, such as Rip Rolls, or licorice ropes, cut into 5-by-1/4-inch lengths, for decorating
White mini nonpareils, for decorating