Preheat oven to 350 degrees
In large mixing bowl, combine sugar, flour, cocoa and salt. Mix until combined.
Add oil, eggs and vanilla.
Beat at medium speed for 3 minutes
Pour into greased 9x13 pan and bake at 350 for 30 minutes
Cool completely
For filling, cream butter and sugars together in a medium bowl.
Add in milk and vanilla
Beat in flour.
Spread over the cooled brownies and chill until firm.
For glaze, melt regular semi-sweet chocolate chips and shortening in microwave. Watch to make sure chocolate chips don't burn. I usually do about 25 seconds and then stir until smooth. Repeat until completely melted.
Spread melted chocolate over filling.
Sprinkle mini chips over chocolate while still warm.
Let cool. Then watch them go!