Preheat the oven to 350°F/175°C. Line two baking sheets with parchment paper.
In a medium mixing bowl, mix the flour, oats, salt and baking soda.
In a separate, large mixing bowl, beat the butter, brown sugar, and sugar until light and fluffy. Beat in the peanut butter, milk, and vanilla until creamy.
Pour the dry ingredients into the wet and mix until just combined.
Fold in the chocolate chips and chunks.
Roll out 3 tbsp dough per cookie onto lined baking sheets. Flatten each cookie slightly. If desired, press more chocolate chunks into the tops of the dough.
Bake for 12-14 minutes – the cookies may look slightly underdone, but they'll cook a bit more while cooling on the baking sheet. Enjoy!
