Preheat the oven to 350°F (175°C) and line the baking tray with parchment paper. Set aside.
In a medium-size bowl, whisk together all-purpose flour, cornstarch, cocoa powder, baking soda, and a pinch of sea salt. Set aside.
In a large bowl using a hand mixer or a stand mixer, beat vegan butter with granulated sugar, and brown sugar on medium speed for about 1 minute until creamy. Add unsweetened almond milk and mix until incorporated. Scrape down the sides and mix again as needed to combine. Add flour mixture, and mix on low until just combined. Add chunks of Oreo cookies and gently fold them in with a spatula or wooden spoon.
Scoop out 10 dough balls (using medium size scoop – 2inch /5cm). Place the cookie dough ball on the prepared baking tray (make some space between them), top with more Oreo chunks (if desired), and bake in a preheated oven for 11-12 minutes.
Take the cookies out of the oven and let them sit on the tray for about 2 minutes. Then transfer them to a cooling rack and let cool for about 10 minutes.
Serve and enjoy!