Line a 9" square pan with non-stick foil with edges hanging over sides. Grease with 1 1/2 teaspoons butter. Set aside.
In a small saucepan over low heat combine whipping cream, coffee granules 2 oz. semisweet chocolate squares. Stir gently until chocolate is melted. Remove from heat and set aside until cool.
In a large heavy saucepan combine remaining butter (1/4 cup) with sour cream and sugar. Cook and stir over medium heat until sugar is completely dissolved. Bring mixture to a rapid boil and cook until candy thermometer reaches 234^ (soft ball stage), approximately 5 minutes.
Remove from heat; stir in white chocolate squares and marshmallow cream (open jar and place in microwave for 10-15 seconds makes for much easier removal) until completely melted.
Stir in orange zest and extract. Pour into prepared pan.
Drop dollops of the coffee/chocolate mixture over orange mixture in pan. Swirl with a butter knife to blend coffee/chocolate mixture throughout fudge.
Chill until firm. Remove foil (using extended handles) and cut into 1" squares.
Yield: 2 lbs.