First, gather all your ingredients. Having everything prepped and ready to go makes the cooking process smoother and more enjoyable. Measure out your sugar, butter, evaporated milk, marshmallows, and chocolate chips. This ensures you won’t be scrambling in the middle of cooking.

In a medium saucepan, combine the sugar, butter, and evaporated milk. Stir it over medium heat until the butter melts and the sugar dissolves. Bring the mixture to a boil, stirring constantly for about 5 minutes. You’ll notice it thickening up nicely.

Remove the pan from the heat. Stir in the marshmallows, white chocolate chips, and vanilla extract. Keep stirring until everything is well combined and the marshmallows and chocolate chips are fully melted.

In a separate bowl, melt the semi-sweet chocolate chips in the microwave in 30-second intervals, stirring in between. Once melted and smooth, add the ground cinnamon and chopped nuts. Stir to combine.

Pour the white chocolate mixture into a parchment-lined 8×8 inch baking dish. Drop dollops of the semi-sweet chocolate mixture on top. Using a knife or a toothpick, swirl the two mixtures together gently. Don’t over-mix; you want to see distinct swirls.

Allow the fudge to cool at room temperature for about 2 hours. You can also put it in the refrigerator if you’re in a hurry. Once set, cut it into squares and enjoy!