While the cakes are cooling, make the frosting by placing the Oreos into a food processor and process into crumbs, set aside.
Place the softened butter and cream cheese into the bowl of a stand mixer with the paddle attachment, and cream together until smooth.
Add the confectioner’s sugar a little at a time until fully combined, and scrape down the sides as needed.
Add the heavy cream and vanilla, and stir it in until combined.
Place the mixer on medium-high speed and whip for 3 minutes until light and fluffy.
Add the cookie crumbs and stir them in until combined. I like to then use a spatula to mix it a little more by hand to make sure the cookie crumbs are evenly distributed.
Cut any doming off the cakes so the tops are flat.
Place one of the cakes - bottom side down - onto your serving platter or cake plate.
Add about 1 cup of the frosting on top and smooth it out to the edge.
Place the second cake - top side down - onto the frosting.
Add a thin layer of frosting over the whole cake for the crumb coat.
Place it in the fridge for 1-2 hours to set up.
Add another layer of frosting around the whole cake.
Take any remaining frosting and decorate the cake as you wish, and add mini Oreos if desired. Cut and serve immediately.