Line an 8x8 inch baking dish with parchment paper and spray with cooking spray.

To make the bottom Butterbeer Fudge Layer: In a medium saucepan over medium-high heat, melt the salted butter, marshmallow creme, sweetened condensed milk, granulated sugar, and caramel syrup, stirring constantly.

Bring to a boil, then set a timer for 4 minutes and stir constantly. The mixture should turn a golden-brown color.

Once boiled, add the butterscotch chips and stir until smooth. Continue whisking for 1-2 minutes until thickened but pourable.

Pour the butterscotch layer into the prepared pan and chill in the freezer for 20 minutes.

For the white chocolate layer: In another saucepan, heat the sugar, butter, marshmallow creme, and condensed milk, stirring continuously.

Bring to a boil, then reduce heat to medium and boil for 2 minutes while stirring.

Remove from heat and stir in white chocolate chips until melted. Pour over the chilled butterscotch layer and smooth the top.

Allow the fudge to set in the refrigerator for at least 2 hours, then cut into 1-inch squares and serve.