Preheat the oven to 355°F/180°C.
Mix vegan butter, white and brown sugar for one minute in a bowl using a stand or hand mixer.
Add oat milk and vanilla extract and mix until just combined.
Add rolled oats, flour, baking powder, and salt and mix using a rubber spatula or spoon. Fold in the chocolate chips.
Take one heaped tablespoon of the dough, form it into a ball, and place it on a with parchment paper lined baking sheet.
Proceed with the rest of the dough and make sure to leave enough space between each cookie, as they will flatten and spread out during baking.
Bake for 12 minutes in the preheated oven.
Take them out of the oven and leave them for another 5 minutes on the baking sheet before you transfer them on a cooling rack to completely cool → Hot cookies directly out of the oven break immediately!