Add 1 ½ cups (355 ml) milk into a sauce pan and heat with a medium-high heat
Meanwhile, cut the dark chocolate bar(s) into small pieces
Once the milk comes to a light boil, reduce the heat to a low-medium heat, add in the pieces of chocolate, whisk together, after 2 to 3 minutes and all the chocolate is fully melted and you end up with a creamy chocolate sauce with no lumps, turn off the heat and set aside
Line an 8-inch (20 cm) circular baking pan with parchment paper and spray with non-stick cooking spray
Add 1 cup (240 ml) milk into a bowl, start coating the cookies, one at a time in the milk, between 6 to 8 flips in the milk, enough to absorb the milk but not get mushy, add into the baking tray, all in a single layer, once you add you first layer of cookies, pour in some of the chocolate sauce, just enough to cover the cookies, gently spread the chocolate so it covers the entire surface, continue to assemble your cake in this method until done, between 6 to 7 layers of cookies will do
Once the cake is fully assembled, cover with saran wrap and add to the fridge between 3 to 4 hours
After at least 3 to 4 hours, remove the cake from the fridge, gently remove from the baking pan and transfer into a serving dish, enjoy!