Heat oven to 350°F. Grease bottom only of 8 or 9-inch square pan. In medium saucepan, melt 1/2 cup margarine and chocolate over low heat, stirring constantly. Cool slightly.
Add sugar and vanilla; blend well. Add eggs; beat well. Lightly spoon flour into measuring cup; level off. Add flour, baking powder and salt; mix well. Spread in greased pan.
Bake at 350°F. for 18 to 23 minutes or until toothpick inserted in center comes out clean. Remove brownies from oven. Set oven to broil.
In small bowl, combine 2 tablespoons margarine, brown sugar, corn syrup and milk; blend well. Stir in coconut and pecans. Drop mixture by teaspoonfuls evenly over warm brownies; spread gently. Broil 4 inches from heat for 1 to 1 1/2 minutes or until bubbly. Cool completely. Cut into bars.