Preheat oven to 375ºF.
Prepare a 9x13 baking dish by lining it with parchment paper. If necessary, foil can be used, but it must be sprayed with cooking spray.
Mix together (using a stand mixer or by hand) the butter, brown sugar, and eggs.
Mix in the milk, vanilla, flour, baking soda, salt, and oats.
Stir in the chocolate chips, Rolos, and pecans.
Spread the dough in the prepared baking dish.
Bake for approximately 20-25 minutes.
The edges should be set and golden brown, and the tops of the bars should look mostly "dry."
Allow to cool for at least 10 minutes before cutting.