Pistachio Swirl Fudge

3 ounces cream cheese
1 (14 ounce) can sweetened condensed milk, divided
1/2 teaspoon vanilla extract
18 ounces semisweet chocolate chips
1 tablespoon sweet butter or margarine
1/2 cup coarsely chopped pistachio nuts

Place cream cheese in small glass bowl of electric mixer or in a 1-quart microwave-safe bowl. Microwave on HIGH (100%) for 15 to 25 seconds or until cream cheese has softened. Add 2 tablespoons of the sweetened condensed milk and vanilla extract. Beat on low speed just until mixture is smooth; set aside.

Place remaining sweetened condensed milk, semisweet chocolate and butter in a 2 1/2-quart microwave-safe bowl. Microwave on MEDIUM (50%) for 2 to 3 1/2 minutes or until mixture can be stirred smooth and is glossy, stirring twice. Stir in pistachio nuts.

Spread chocolate mixture evenly into prepared pan. Drop cream cheese mixture, by spoonsful, over chocolate; swirl lightly over chocolate. Let stand until firm or place in refrigerator. Cut into 25 even squares by making 4 lengthwise and 4 crosswise cuts equidistant from each other, then cut each square diagonally in half. Store in airtight container with wax paper between layers. Keeps best if refrigerated.

Makes 50.