Heat oven to 350°F Spray 9-inch square pan with nonstick cooking spray. Beat egg in large bowl. Add all remaining coffee cake ingredients except chocolate chips; mix well. Beat 30 strokes with spoon. Fold in chocolate chips. Pour into sprayed pan.
In small bowl, combine all streusel ingredients; mix well. Crumble mixture over batter.
Bake at 350°F for 28 to 33 minutes or until toothpick inserted in center comes out clean. Cool 30 minutes before serving.