Heat oven to 350°F. Grease bottom and sides of 13x9-inch pan with shortening or cooking spray (do not use dark pan). In 3-quart saucepan, heat baking chocolate and butter over low heat, stirring frequently, until melted and smooth. Cool 5 minutes.
Meanwhile, in medium bowl, beat cream cheese, 1/2 cup of the sugar and 1 of the eggs with electric mixer on medium speed until smooth. Set aside.
Into chocolate mixture, stir remaining 2 cups sugar, remaining 4 eggs and the peppermint extract. Stir in flour and salt until well mixed. Spread half of chocolate batter in pan. Drop cream cheese filling by teaspoonfuls over batter. Carefully spoon and spread remaining batter over filling.
Bake 40 to 45 minutes or until toothpick inserted in center comes out clean. Sprinkle evenly with baking chips. Cool completely, about 1 hour 30 minutes. For brownies, cut into 8 rows by 6 rows. Store in refrigerator.