A very thin crust forms over the surface of the fudge while you microwave the white chocolate mixture. Don't be alarmed—once you swirl the two together, it will become smooth again.
Southern Living DECEMBER 2008
1. Line bottom and sides of an 8-inch square pan with parchment paper, allowing 2 to 3 inches to extend over sides.
2. Microwave butter in a large microwave-safe glass bowl at HIGH for 30-second intervals until melted. Gently stir in powdered sugar and next 3 ingredients. (Mixture will be lumpy.) Microwave 30 seconds; add vanilla.
3. Beat mixture at medium-low speed with an electric mixer until well blended and smooth. Pour into prepared pan, spreading to edges of pan.
4. Microwave white chocolate and whipping cream in a small microwave-safe glass bowl at HIGH until white chocolate is melted (about 30 seconds to 1 minute), stirring at 30-second intervals. Stir until mixture is smooth. Let stand 1 to 3 minutes or until slightly thickened. Spoon mixture over fudge in pan, swirling with a paring knife. Cover and chill until firm (about 2 hours).
Note: We tested in an 1,100-watt and a 1,250-watt microwave oven. Cook times will vary depending on your microwave wattage; be sure to follow the descriptions in the recipe for best results.
Go to full version of