Line a 9-inch square baking dish with parchment paper. Set aside.
In a large mixing bowl, add marshmallow fluff, package of white chocolate morsels, cinnamon, ginger, nutmeg, and cloves. Set aside (no need to mix yet).
In a large saucepan, melt butter over medium high heat. Add in sugars, molasses, and heavy cream. Bring to a boil while stirring continuously.
Once boiling, continue to stir (and boil) for a full 5 minutes.
Remove from heat and pour over marshmallow mixture in a mixing bowl. Blend for one minutes, until white chocolate is melted. Pour into prepared dish.
Melt 1 cup of white chocolate and immediately drizzle over fudge (while warm). Add sprinkles. Refrigerate for at least 2 hours.
Notes
Store in refrigerator or room temperature for up to 2 weeks.
For best texture, only cut pieces as you need them, it keeps the fudge from drying out.