Line an 8x8 baking dish with parchment paper (leave the edges hanging off the sides so you can lift the fudge out the dish) and set aside.
Add together the sugar, butter and heavy cream into a large sauce pan, bring to a boil over medium heat.
Reduce the heat to medium low, cook for 7 minutes, stirring constantly.
Work very quickly during this step: Remove the pan from the heat and immediately mix in the white chocolate chips. Stir until the chips are fully melted and mixed well. Add the marshmallow creme and mix well to combine. Add the vanilla extract and stir once again.
Pour into the prepared 8x8 pan. Instantly sprinkle the crushed sugar cones all over on top, lightly pressing down on them so they stick to the fudge. Let cool at room temperature for about 30-45 minutes.
Lift the parchment paper and fudge out of the baking dish once set and slice into equal squares. In a microwave-safe bowl, add the semisweet chocolate chips and oil. Microwave in 30-second increments, stirring in between, until fully melted.
Prepare a sheet pan with parchment paper. Working one square at a time, dip the bottoms of the fudge into the chocolate, then dip the chocolate into the crushed peanuts. Set each square down on the parchment paper to dry. Repeat until all the fudge is coated.
Let the chocolate harden for about 1 hour, then serve!
NOTES
Store in an airtight container for 3-4 days on the counter. You can crush the sugar cones as thin and fine as you’d like. You can speed up the drying time by placing the chocolate-covered fudge in the fridge until hardened.