Start by making the butterscotch layer. Combine the sugar, butter, and heavy cream in a saucepan. Cook over medium heat, stirring until the butter is melted.
2 1/2 cups sugar, 3/4 cup butter, 3/4 cup heavy cream
Bring to a rolling boil and boil for 5 minutes, stirring constantly. Remove from heat and stir in the butterscotch chips.
11 ounces butterscotch chips
When all the chips are melted, add the marshmallow creme and rum extract and mix well.
7 ounces marshmallow creme, 1 tsp rum extract
Spread the mixture in a parchment paper lined 8×8 inch pan. Place in the freezer to set while you make the white chocolate layer.
To make the white chocolate layer, combine sugar, butter, and heavy cream in a saucepan. Cook over medium heat until the butter is completely melted.
1 1/4 cups sugar, 6 Tbsp butter, 6 Tbsp heavy cream
Bring the mixture to a rolling boil and boil for 5 minutes, stirring constantly. Remove from heat and stir in white chocolate chips.
1 cup white chocolate chips
When all the chocolate is melted, stir in the marshmallow crème and vanilla extract and stir until well combined.
1/2 cup marshmallow creme, 1/2 tsp vanilla extract
Spread the white chocolate mixture over the butterscotch layer and chill in the refrigerator for 2-3 hours before slicing.
Once the butterbeer fudge is chilled, cut it into squares. I found that cutting 30 squares gave you the perfect bite size pieces.