Place the cashews, rolled oats, 10 pitted dates, cocoa powder, and 1 tablespoon of milk in a blender or food processor. Process until a uniform, slightly sticky dough forms. Press the mixture firmly and evenly into an 8-inch/20 cm square pan lined with parchment paper so the base is compact and level.

Combine 5 pitted dates, 1/2 cup peanut butter, 1/2 cup milk, and coconut oil in the blender. Process until completely smooth and creamy, scraping down the sides once. Gently pour the peanut butter cream over the pressed base and spread it evenly with an offset spatula, keeping the layer level.

Add 5 pitted dates, cocoa powder, 1 tablespoon peanut butter, and coconut cream to the blender. Blend until silky and chocolatey. Pour the chocolate cream over the peanut layer and smooth it to an even surface.

Warm a little peanut butter so it is pourable and drizzle it over the top. Use a skewer or toothpick to create decorative swirls if desired. Cover the pan and transfer to the freezer for at least 2 hours to set before slicing. For easy serving, place each piece in a paper liner. Store in the freezer.