Step 1

Line an 8x8 inch square pan with foil or parchment paper and spray with cooking spray.

Step 2

In a double boiler, add 1 1/2 cups semi-sweet chocolate chips, 1 1/2 cups milk chocolate chips, butter, sweetened condensed milk, and hot chocolate mix. Stir to combine.

Step 3

Continue to stir over medium heat until the chips are completely melted.

Step 4

Add 2 cups of marshmallows and stir for 1 minute. Remove from the heat.

Step 5

Add in the vanilla and stir until incorporated.

Step 6

Pour the fudge into the prepared pan and gently press the remaining marshmallows into the top of the fudge.

Step 7

Refrigerate for 4 hours.

Step 8

Remove the fudge from the pan and cut it into squares.

Step 9

Heat the remaining 1/2 cup of chocolate in the microwave in 30-second intervals, stirring after each interval until completely melted.

Step 10

Drizzle over the fudge and let cool completely.