Line a 9 x 9 baking dish with foil.  Set aside.

In a saucepan over medium low heat combine the milk chocolate chips and half the sweetened condensed milk.  Heat, stirring frequently, until the chocolate is completely melted and combined. 

Remove from heat and stir in the sea salt.  Pour into the prepared pan.

In a saucepan over medium low heat combine the white chocolate chips and the other half of the sweetened condensed milk.  Heat, stirring frequently, until completely melted and combined.   Pour over top of the chocolate fudge in the pan.

Quickly top the white chocolate fudge with the micro marshmallows and then sprinkle with hot chocolate mix. 

Put in the refrigerator and chill for at least 4 hours. 

Remove from the pan and cut into 24 squares.