Preheat the oven to 350 degrees Fahrentheit. Line a baking sheet with parchment paper.
Whisk the melted butter and both sugars together, then add vanilla and almond milk in a medium bowl.
Place the oat flour, brown rice flour, tapioca starch, baking soda, and salt in a separate mixing bowl and whisk well to combine.
Slowly add the dry ingredients to the wet, stirring until dough forms. Fold in the chocolate chips and transfer bowl to refrigerater to chill for 30 minutes. (Dough will be loose before chilling. After chilling it may have a sheen on top that makes it look more liquid-like. Do a test scoop - it should be solid enough after 30 min.)
Use a tablespoon or similar-sized scoop and drop cookie dough into even rows on cookie sheet about 2 inches apart.
Bake for 10-12 minutes. (11 minutes gives a nice, soft middle) Allow cookies to cool for 5 minutes on cookie sheet then transfer to a wire rack.