FOR THE TREATS

6 cups crispy rice cereal

1/2 cup mini marshmallow bits, optional

3 tablespoons butter or margarine

10 ounces marshmallows

2 teaspoons finely grated orange zest

FOR THE FROSTING

1/2 cup (1 stick) unsalted butter, at room temperature

2 cups (250 grams) confectioners’ sugar

2 tablespoons heavy cream

1 tablespoon finely grated orange zest

2 to 3 teaspoons orange juice

Food coloring (optional)