-
Preheat oven to 375F degrees
-
In a small bowl, mix flour, cocoa, baking power, and salt
-
In a large bowl, mix together butter and sugar until creamed (about 2-3 minutes), then add egg, milk, vanilla and mix
-
Slowly add dry ingredients from small bowl
-
Grease a 9x13 cake pan and press cookie dough into the bottom (I used my hands then a fork to spread evenly!)
-
Bake for 15 minutes and cool
-
Meanwhile, combine all icing ingredients, except chocolate/mint chips, and mix until fluffy
-
Remove cookie bar from pan and spread evenly with icing
-
Cut into squares
-
Melt chocolate/mint chips in a small bowl in the microwave in small time increments (15-20 seconds, stirring in between)
-
Drizzle chocolate over the squares