Preheat oven to 350 degrees. Spray a 9x13 inch with nonstick cooking spray.
In a bowl, beat the butter, brown sugar and eggs together. Add the vanilla and milk and mix to combine.
In another bowl, whisk the flour, oats, baking soda, and salt together. Add it in to the butter mixture and mix well.
Spread 2/3 of the mixture into the bottom of the prepared 9 x 13 pan and set aside.
In a saucepan, add all of the fudge ingredients. Cook over medium heat until completely melted and combined. Once melted, pour over the 2/3 cookie mixture in the pan.
Next, drop spoonfuls of the remaining cookie dough over the top of the fudge. You wan t fudge peeking out in between the spoonfuls of cookie mix.
Place the oven at 350 degrees and bake for 25 minutes. If the top is getting browned after 15 minutes, cover with foil. Allow to cool completely or the fudge won't remain in the middle. Cut into squares.