01 -
In a microwave-safe bowl, combine the semi-sweet chocolate chips and butter. Melt in 30-second increments, stirring between each, until fully melted.
02 -
Add vanilla extract and sweetened condensed milk to the melted chocolate mixture and stir until evenly combined.
03 -
Line a square baking dish with parchment paper. Pour the fudge mixture into the dish and smooth out the top with a spatula.
04 -
Add dollops of Nutella and marshmallow spread on top of the fudge. Use a toothpick, knife, or skewer to gently swirl the toppings into the fudge.
05 -
Place the baking dish in the refrigerator and let the fudge set for about 3 hours.
06 -
Remove the fudge from the fridge, cut it into squares, and enjoy.