1Heat chocolate chips and milk in 1-quart heavy saucepan over low heat, stirring frequently, until chocolate is melted and mixture is smooth; set aside. Heat oven to 350°. Spray square pan, 8x8x2 or 9x9x2 inches, with cooking spray.
2Mix flour, 1/2 cup oats, the baking powder, baking soda and salt in large bowl; set aside. Stir brown sugar, oil, vanilla and egg product in medium bowl with fork until smooth; stir into flour mixture until blended. Reserve 1/2 cup dough in small bowl for topping.
3Pat remaining dough in pan (spray fingers with cooking spray or lightly flour if dough is sticky). Spread chocolate mixture over dough. Add 2 tablespoons oats and the butter to reserved dough; mix with pastry blender or fork until crumbly. Drop small spoonfuls of oat mixture evenly over chocolate mixture.
4Bake 20 to 25 minutes or until top is golden and firm. Cool completely, about 1 1/2 hours. For bars, cut into 4 rows by 4 rows.