In a large bowl, or the bowl of a stand mixer, cream the butter, granulated sugar and brown sugar for about 5 minutes until light and fluffy. Add milk, vanilla and salt and mix until completely combined.
Stir in flour until well combined, then add mini chocolate chips and fold until evenly distributed. Set cookie dough aside while you prepare chocolate layer.
Line a cookie sheet with parchment paper and make sure there is a spot in your freezer where it can lay flat. Melt chocolate coating according to the package directions. (It is usually easiest in the microwave.)
Pour half of the melted chocolate into center of parchment paper and spread it out into a 9" x 12" rectangle, which should make the chocolate about 1/8" thick. Place cookie sheet in freezer to harden—it should only take about 5 minutes.
Remove first layer of hardened chocolate from freezer and spread cookie dough in an even layer to cover entire surface of the chocolate. Spread remaining melted chocolate evenly over the top of the cookie dough.
Return the pan to freezer until completely set. Break up the bark into pieces and serve or store in the refrigerator until ready to eat. Enjoy!
One Last Thing
Sprinkling the cookie dough with a little sea salt adds big flavor!