Heat oven to 350 degrees. Grease 13 x 9-inch baking pan. In mixer bowl. beat flour, sugar, melted butter, cocoa, 2 eggs, milk, 2 tsp. vanilla and baking powder until well blended. Stir in nuts. Spread into pan. In small mixer bowl, beat cream cheese, 2 T butter and cornstarch until fluffy. Gradually add sweetened condensed milk, then remaining 1 egg and 1 tsp. vanilla, beating until smooth. Pour over brownie batter. Bake 35 to 40 minutes or until top is lightly browned. Cool; refrigerate. Cut into bars. Store covered in refrigerator. ----