First up: Keep the ice cream out of the fridge for sometime to be melted substantially for easy applying & coating the ice cream cake- In different layers

Keep the springform pan ready & it should be placed on a firm surface (plate/dish/wooden platform, etc.)

In a airtight sealed pouch bag: Crush the Oreo & Multigrain Cookies/Biscuits, both together or one kind, at a time...pour in some melted butter to it to keep its base firm & prevent any form of leakages

The cookies/biscuits to be crushed absolutely to a smooth powder form (which’s the very base of this ice cream cake- Mix with the butter well & pour it out into the pan & line up the pan base with it to form a firm base for this cake

Gently press & spread it out all along & flatten it with a big spoon/ladle or a silicon spatula- Let it rest in the fridge for about 10 mins time

Once done take it out & in the interim Slice a few more Oreo Cookies into 2 halves- Lengthwise, set aside for its later use & also roughly crush/crumble a few more of the same to be mixed with the Vanilla ice cream layerings to give it an absolute decadent taste

Ensure, while freezing it inside the freezer- you need to keep it covered always to avoid forming of the ice crystallisations on its top, giving it a shabby & uneven textures & looks...

Now, pour in the melted chocolate ice cream as the first layer of the cake- tap it a few times to get evenly spread all along, arrange the sliced Oreo cookies for a nice look & immensely delectable tastes

Again, put it back into the freezer now, for about 2-3 hrs time to get it set & firm completely before we add in the 2nd layer of the Vanilla & Oreo Cookies ice cream base (this is supposed to be the top base of the cake)

Once done take it out: Now, pour into it it’s final or the topmost layer of the Vanilla-Oreos Ice Cream base...Garnish with some white choco chips & a handful of shredded walnuts- Garnish it your very own ways to not only look good but also, taste absolutely amazingly marvellous inside one’s mouth

Put it again back to the freezer for now, at least: 4-6 hrs time or overnight is always better for its excellent textures & looks both...Needless, to mention- that this way, it simply tastes amazingly out of the world...
Don’t believe in what I say... Prepare it on your own, ASAP