Preheat oven to 350 degrees. Line a cookie sheet with parchment paper or a silicone baking mat and set aside.

Combine the Oreo crumbs and melted butter and stir until well combined. Spread the crumbs evenly onto the prepared cookie sheet.

Bake for 8-10 minutes, then allow to cool. Use your fingers to break any big clumps into smaller ones. Set aside.

To make the cheesecake filling, add the cream cheese and sugar to a large mixer bowl and mix until well combined and smooth.

Add the cocoa powder and mix until well combined.

Add the Baileys, vanilla extract and salt and mix until well combined and smooth. Set aside.

To make the whipped cream, add the heavy whipping cream, Baileys, cocoa powder, powdered sugar and vanilla extract to a large mixer bowl. Whip on high speed until stiff peaks form.

To make the trifles, divide half of the cookie crumbs evenly between the four cups or jars and spread into an even layer in the bottom of the cups.

Pipe, or spoon, an even layer of cheesecake filling on top of the cookie crumbs in each of the four cups. You should only use about half of the filling.

Pipe, or spoon, an even layer of whipped cream on top of the cheesecake filling in each of the four cups.

Divide remaining cookie crumbs between the four cups and evenly distribute the second layer of crumbs on top of the whipped cream. You can keep a little bit of crumbs aside, if you want to use them to sprinkle on top of the finished trifles.

Pipe, or spoon, remaining cheesecake filling on top of cookie crumbs, distributing evenly between the four cups.

Top each trifle with a swirl of whipped cream and a few more cookie crumbs, if desired.

Refrigerate until ready to serve. Best if eaten within 2-3 days.