Cover a 9 x 9 pan with foil and set aside.

In a large saucepan combine the butter, sugar, and half and half. Bring to a boil, stirring frequently, then reduce heat to a simmer.

Simmer, stirring constantly, for 5 minutes.

Add in the marshmallow fluff and stir until combined.

Remove from heat and stir in the white chocolate chips until melted.

Mix together the chocolate chips and red food coloring in a large bowl. Add in half of the white chocolate mixture and stir until the chocolate chips are melted.

Add half of the white chocolate mixture to the prepared pan. Add dollops of red chocolate mixture on top of the white chocolate. Add the remaining white chocolate mixture and top with dollops of the remaining red chocolate mixture.

Use a butter knife and swirl the two chocolate fudge mixtures together into a pretty pattern.

Place fudge in refrigerator for 2 hours.

Remove from refrigerator and remove the fudge from the pan using the foil. Cut into squares and enjoy!