In a mixing bowl, add the bread flour, baking powder, baking soda, and salt and mix well. Then add the oats and mix once again.

In the bowl of a stand mixer fitted with a paddle attachment (or you can use a bowl and a hand mixer), add the butter and sugar. Beat for 2-3 minutes or until paste-like in consistency and pale beige in color.

Then, add the egg and vanilla and beat until well incorporated and emulsified.

Add half of the dry mixture and mix on the lowest speed until no dry ingredients are left. After, add the milk and mix to incorporate.

Add the rest of the dry ingredients and mix on low until fully combined.

Fold in the chocolate chips and place the bowl with the cookie dough in the fridge while the oven is preheating.

Preheat the oven to 355F (180C) and line a baking sheet with parchment paper.

Scoop 20 cookie dough balls (I used a 2-tablespoon cookie scoop) onto the prepared baking sheet leaving 1.5" in between. Bake for 12 minutes or until the cookies have spread, puffed up, no longer look wet, and turned a golden-brown color around the edges. If baking in batches, keep the rest of the dough in the fridge.

Remove from the oven and let them cool down for 5 minutes on the tray. Then, transfer onto a cooling rack to cool down completely. Bake another batch of the cookies.