Line an 8 or 9-inch square baking dish with parchment paper. Set aside.
In a large bowl (for a stand mixer), add white chocolate chips and the jar of marshmallow cream. Set aside.
In a large saucepan, melt butter with sugar, heavy cream and salt. Cook and stir over medium heat until mixture begins to boil. Boil for 4 minutes, stirring continuously.
While mixture is boiling, add caramel bits and 1 tsp heavy cream to a microwave safe bowl. Heat for 30 seconds and stir. Repeat 3-4 times until smooth and melted (mine took a total of 2 minutes).
Remove butter mixture from heat after 4 minutes of boiling and pour over white chocolate chips mixture in bowl.
Beat for about one minute using the whisk attachment, just until white chocolate chips are melted.
Add in melted caramel and stir once with wooden spoon.
Pour into prepared baking dish.
Let set for 4 hours (or overnight).
Cut into bite size pieces and enjoy.
Notes
Line your baking dish with parchment paper before adding the fudge mixture. Once the fudge is set, you can grab the corners of the paper to remove it from the pan and cut squares for serving.
Slice as you go. Only cut your fudge as you plan to use it. This helps keep the remaining block as fresh as possible.
Store fudge at room temperature in an airtight container for up to 1-2 weeks.