Prepare brownie mix as package directs. Spread into well-greased 13 * 9-inch baking pan.
In a small mixing bowl, beat cheese, margarine and cornstarch until fluffy. Gradually
beat in sweetened condensed milk then egg and vanilla until smooth.
Pour evenly over brownie batter. Bake for 45 minutes or until top is lightly browned.
Cool.
Spread with frosting if desired. Cut into bars. Store in refrigerator.
Makes 36 to 40 brownies
Preparation time: 1 hr