Preheat your oven to 350° F.
In the bowl of a stand mixer or with an electric hand mixer, cream together the butter and brown sugar until completely combined.
Add in the eggs and milk. Mix until creamy.
Next, add in the whole wheat flour, rolled oats, salt, baking powder, and baking soda. Mix until a sticky dough forms
Mix in the chocolate chips until distributed evenly.
Portion out the dough for your desired cookie size. 1 1/2 tbsp of dough for small cookies, 3 tbsp of dough for medium cookies or 1/3 cup of dough for large cookies.
Roll into a ball and arrange on a parchment paper or silicone mat covered cookie sheet.
Bake at 350° until the cookies spread, flatten and just begin turning golden brown on the edges. For small cookies: 7-9 minutes. Medium cookies: 9-11 minutes. Large cookies 12-14 minutes.
Allow the cookies to cool on the pan for 15 minutes before transferring to a wire rack.
Serve warm + enjoy!