Delightfully rich, this festive dessert has a brownielike texture accented with sweet, creamy mascarpone cheese.

Preheat oven to 350 degrees. Grease a 9-inch tart pan with removable bottom; set aside.

In small heavy saucepan, melt chocolate and margarine over low heat, stirring frequently. Remove from heat.

In medium bowl, beat eggs and vanilla with electric mixer at medium speed for 30 seconds. Gradually beat in sugar; beat 1 minute. Beat in chocolate mixture, scraping down sides of bowl once. Beat in flour and salt at low speed just until blended. Spread batter evenly in prepared pan.

Put cheese into small bowl and stir well with a fork. Drop by teaspoonfuls randomly over surface of chocolate batter. Using a sharp knife, swirl cheese mixture into chocolate mixture to create a marbling effect.

Bake until center is just set, 20 to 25 minutes. Remove pan to wire rack and cool completely. Cover tart with plastic wrap; place in large plastic freezer bag and freeze up to 6 weeks before serving.

To Serve: Thaw tart completely at room temperature. Remove from tart pan. Cut into wedges and serve.

Per Serving: 233 Cal.; 4G Prot.; 16G Total Fat (7G Sat. Fat): 23G Carb.; 44MG Chol.; 155MG Sod.; 12G Fiber.