Line an 8-inch square baking dish with parchment paper. Set aside.

In a medium saucepan, heat butter, sugar, salt and heavy cream over medium high heat.

Bring to a rolling boil while stirring constantly.

Set timer and boil for a full FOUR minutes (keep stirring).

Place vanilla extract, white chocolate morsels, and marshmallow cream in a large mixing bowl.

Pour boiling butter mixture over morsels.

Turn electric mixer on medium and combine until white chocolate is melted and smooth.

At this point you can either pour this mixture into your prepared pan. Top with the raspberry preserves and swirl it in with a knife, working quickly.

Or you can pour all but about 1 cup of fudge into the pan. To the remaining fudge, add the raspberry preserves and combine quickly, pour over fudge in pan.

Refrigerate for 3 hours.

Cut into bites and serve.

Store in an airtight container in refrigerator up to two weeks.