For the brownie batter, mix the all-purpose flour, cocoa powder, and sugar in a large mixing bowl. Add the plant-based milk and coconut oil. Whisk until combined. Fold in half of the Oreo chunks.
Transfer the brownie batter into a brownie pan* lined with parchment paper. Add the rest of the oreo chunks on top.
Bake the brownies in the oven for 20 minutes until the top is smooth and a wooden toothpick comes out clean.
Let them cool off, then cut them into 9 pieces and serve!