Heat oven to 350°F. Spray 8-inch square pan with nonstick cooking spray.
In medium bowl, combine margarine, sugar and 2 tablespoons cocoa; mix well. Add eggs 1 at a time, beating well after each addition. Stir in vanilla.
Lightly spoon flour into measuring cup; level off. Add flour and 1/2 cup malted milk powder; stir just until moistened. Spread batter in spray-coated pan.
Bake at 350°F. for 14 to 18 minutes or until toothpick inserted in center comes out clean. DO NOT OVERBAKE. Cool completely.
In small bowl, combine all glaze ingredients except milk; mix well. Stir in milk until well blended. Spread glaze over bars.