In a large saucepan, melt butter with sugar, heavy cream, and salt. Cook over medium-high heat until mixture starts to boil. Stir constantly and boil for 5 minutes.
Remove from heat.
Using a mixer, beat in white chocolate morsels and marshmallow creme until fully blended and smooth, about 1-2 minutes. Pour half the mixture into a parchment paper-lined 9-inch baking dish.
To the remaining mixture, beat in strawberry gelatin mix and continue beating for 1 minute until smooth. Pour this over the first layer and use a knife to quickly swirl the two layers together.
Allow the fudge to set at room temperature for 4 hours or overnight. Cut into bite-sized pieces and enjoy.
Notes
This strawberry swirl fudge is perfect for gifting or celebrations. Store in an airtight container at room temperature.