In large bowl, whisk together flour, brownie mix and brown sugar.
Using a heavy spoon, stir in eggs one at a time. Add melted and
cooled butter and 2 tablespoons cold water. If the batter appears as
if it has too much flour, add 1 more tablespoon of water. Batter will
be very thick, more like cookie batter than brownie batter. Next fold
in chocolate chips. Cover with plastic and chill 2 hours