In the food proccesor, combine the peanuts and cookies, pulse until it's smooth and well combined. It should resemble a coarse flour.
Add the sugar, pulse. Add the condensed milk and process until it forms a ball of dough. Transfer to a baking dish lined with wax paper.
Using your hands, press it very well to form an even layer. Let it rest for at least 15 minutes up to overnight.
Remove from the dish and cut into squares. Keep it in airtight containers.