Preheat oven to 350 degrees.
Grease bottom only of a 9 x 13 inch pan.
In a large bowl combine brownie mix, water, oil, and egg, beating 50 strokes by hand.
Stir in 1/2 c chocolate chips.
Spread in pan and bake for 33-35 minutes.
*DO NOT OVERBAKE*
Cool completely.
In a large bowl, beat 1/2 c butter and sugars until light and fluffy.
Add milk and vanilla, mix well.
Spread over cooled brownies.
In a small microwave safe bowl melt 1 c chocolate chips and 1 T shortening just until melted, stirring until smooth.
Carefully spoon glaze over filling. Spread to cover.
Sprinkle with walnuts, pressing down slightly.
Cut in bars. Store in refrigerator.