Pop popcorn into two very large mixing bowls, set aside. Melt butter in a large saucepan over medium heat. Stir in sweetened condensed milk, cream, sugar, salt and orange zest. Bring mixture to a boil, stirring frequently. Boil mixture one and a half minutes, stirring constantly. Remove from heat. Add in marshmallows and stir until melted. Mix in orange extract. Divide warm mixture evenly over two bowls of popcorn and toss with a spatula to coat. Allow to rest 20 minutes to set.
